On Saturday, Czech police published photos of two foreign citizens who visited the country in 2014 and asked the public for any information about them.

The two were using Russian passports and were identified as Alexander Petrov, 41, and Ruslan Boshirov, 43.

It came as the Czech Republic said it was expelling 18 Russian diplomats who it had identified as spies in a case related to a huge ammunition depot explosion in the town of Vrbetice in 2014.

The foreign secretary said: “The UK stands in full support of our Czech allies, who have exposed the lengths that the Russian intelligence services will go to in their attempts to conduct dangerous and malign operations in Europe.

“This shows a pattern of behaviour by Moscow, following the Novichok attack in Salisbury. My sympathies are with the families of the victims in Vrbetice.

“We are as determined and committed as ever to bring those responsible for the attack in Salisbury to justice, and commend the actions of the Czech authorities to do the same. Russia must desist from these actions, which violate the most basic international norms.” 

Boris Johnson risks losing his election gains against Labour if he does not clean up the “shameful” Westminster lobbying controversy, a Tory MP has warned.

Sir Bernard Jenkin, chair of the Commons Liaison Committee, has urged the PM to get a grip on the lobbying system following a series of revelations in the wake of Greensill Capital’s collapse into administration.

A failure to be “more transparent” than previous administrations could risk the so-called “red wall” seats that Mr Johnson built his 2019 majority on, Sir Bernard suggested.

Writing in The Observer, he said the “lines between public service and private gain” had become “blurred”.

The senior Tory described the current situation as “shameful” and “utterly corrosive of public trust in government”.

In an apparent dig at the former Remain-backing Cameron government, he added: “This should matter to Boris Johnson.

“He does not need to pretend to be a saint, but his ‘red wall’ voters, who gave him his majority, will start to dismiss him unless he can show he is more open, more transparent and very different from the out-of-touch elite he defeated in the 2016 referendum and ousted from government.”

The leader of the Liberal Democrats backed Labour’s call for an independent process to look at whether ministers have broken their code of standards.

Sir Ed Davey, denying that he lobbied government while working for a renewable energy company while out of politics between 2015 and 2017, told the BBC’s Andrew Marr Show: “I’m very worried that the ministerial code isn’t properly enforced.

“We’ve seen (Sir) Alex Allan, the independent adviser for ministerial standards, resign and not been reappointed.

“I’d like to see an independent body enforcing the ministerial code, not the prime minister – that’s wrong.

“It’s wrong that a politician should be the judge and jury of who decides who has broken the ministerial code, and what I would like to see is an independent body, just like we have IPSA over MPs pay and expenses, that could say: ‘this minister has broken the code’ and whether they can’t have their ministerial pay.

“That would be the sort of penalty that I think the public would like and would rebuild trust in British politics.”

Sir Ed, who served in David Cameron’s cabinet during the coalition government, said he wanted to see the result of the investigations into the Greensill Capital affair, but added: “I don’t like the sound of it, we need much greater transparency, as David Cameron once called for.”

The shadow chancellor of the Duchy of Lancaster, Labour’s Rachel Reeves, joined her colleague Steve Reed in claiming “Tory sleaze is back” amid the growing lobbying scandal, which she warned was the “tip of the iceberg”.

Ms Reeves told the Andrew Marr Show on the BBC: “What we’ve seen this week is that Tory sleaze is back and that it is bigger than ever and we need real change to restore trust in our democracy and in the very essence of public service which matters to so many of us and matters to people in our country.

“What we want to see – we wanted this week, and that is why we had a vote on it – to have a proper inquiry.

“Not chaired by one of Boris Johnson’s friends, a very close friend of the Conservative Party is Nigel Boardman who is doing the review, but a proper independent inquiry that has teeth and has the chance to make recommendations on how to clean this up.

“Because this isn’t just about Greensill, Greensill is the tip of the iceberg.”

The government is launching an American-style “culture war” to divide communities and the Labour Party must not be “complicit” in this inflammatory rhetoric, a Labour MP has warned.

Zarah Sultana, who represents Coventry South, accused ministers of denying racism is a problem in the UK and argued their recent pledges to tackle violence against women in the wake of Sarah Everard’s killing amount to little more than “spin and empty promises”.

The 27-year-old told The Independent the UK government is seeking to provoke a so-called culture war, reminiscent of recent US political discourse, in a bid to “keep control”.

Labour’s Steve Reed said “Tory sleaze” was back following revelations about Greensill Capital and other ministerial links to private businesses.

The shadow communities secretary and Croydon North MP told Sky News’s Sophy Ridge On Sunday: “From what I can see in all this is that the era of Tory sleaze is well and truly back.

“And what’s happened with the Greensill scandal is really quite shocking.”

Boris Johnson should not visit India later this month as he currently plans to, Labour has said. 

The shadow communities secretary, Steve Reed, said: “I can’t see why the prime minister can’t conduct his business via Zoom.” 

The prime minister will attend talks in the country on 26 April, in spite of their spiking Covid-19 cases.

There are also concerns about a Covid variant first identified in India spreading further. More than 70 cases of the variant have already been tracked in the UK.

George Eustice said “no” when asked if David Cameron did anything wrong amid the growing lobbying scandal.

Asked about former prime minister’s conduct, Mr Eustice told Sky’s Sophie Ridge On Sunday: “Well look, he himself has said that with hindsight it probably would have been better if, rather than texting ministers, if he had instead written letters to set out his views more formally.

“But I think the real point is. ‘has he done anything wrong?’ Well, on the face of it, no. There’s a review that is going on, we mustn’t prejudge that.”

Pushed on whether Mr Cameron exploited the rules, Mr Eustice added: “I don’t think he took advantage of any rules, no. He meticulously observed the rules there that he himself actually put in place after some concerns around lobbying a decade ago.

“He put in place these restrictions on what ministers can do for a period of two years.

“But look, he himself has conceded that with hindsight, if he had his time again, he wouldn’t have texted Rishi Sunak and wouldn’t have texted others – he would instead have written through formal channels.” 

George Eustice said Matt Hancock had followed the rules when it came to declaring an interest in a family company that has contracts with the NHS.

The health secretary declared in the MPs’ register of interests in March this year that he owns more than 15 per cent of shares in Topwood Limited, a firm which specialises in secure storage, shredding and scanning of documents.

Mr Eustice told the Sophy Ridge On Sunday programme: “The reason we know about this is because Matt Hancock did what all ministers do in this case, which is to declare that interest.

“And so he did the right thing, he declared that – he had no role whatsoever around that business, so yes there is nothing wrong with ministers having financial interests, providing they declare them in the appropriate way.”

Asked whether lobbying rules were “broken” if they allowed ministers to hold financial interests in companies making money from their government department’s contracts, the Cabinet minister replied: “I’m not sure I would agree with that.

“Ministers can move around a lot – famously we tend not to spend too long in one particular role.” 

George Eustice has said the government would be looking at whether changes were required to lobbing rules after a series of probes had finished, but added that the current system for declaring interests was “pretty good”.

The environment secretary told Sky News’ Sophy Ridge On Sunday: “I think the right thing is for these reviews to go through their process, to conclude, to work out exactly what did and what did not happen and then yes, of course there may come a time after that when it is right to consider tweaks to policy.

“But fundamentally, I think the systems we have in place with ministers declaring interests with the ministerial code and the focus on that and how ministers conduct themselves in office is actually a pretty good one.

“But that is not to say you couldn’t make tweaks or changes, and also there will be a time and a place for that after these reviews have concluded.”