The High Court is due to hear two legal challenges over the use of WhatsApp and other messaging apps by ministers.

Campaign groups All the Citizens moved the court arguing that the use of instant messaging apps such as WhatsApp and Signal, which allow the messages to be deleted automatically, for government business is unlawful.

In their separate claim against prime minister Boris Johnson, the Good Law project is expected to argue over the use of non-government communication channels.

Lord Justice Singh and Mr Justice Johnson are to hear the claims for three days.

The Metropolitan Police have begun interviewing key witnesses in the Partygate scandal, with Scotland Yard announcing it has sent over 100 questionnaires to Downing Street and Whitehall staff asking them about gatherings during the Covid lockdowns.

“In addition to the detailed review of all available material, including returned questionnaires, detectives from the Operation Hillman investigation team have started interviewing key witnesses,” said a Met Police spokesperson.

The Independent has learnt that Mr Johnson, who returned his questionnaire to investigators last month, has not been called for an interview.

Read the details about the Partygate investigation in this report by Adam Forrest:

Conservative MP Kit Malthouse is being criticised for a “distinct lack of urgency” after he repeatedly said that the government must wait for the police watchdog report investigating the strip search of a Black schoolgirl.

While the minister for policing and crime condemned the “distressing” incident, he insisted that the government wait for the report by the Independent Office for Police Conduct to get a sense of “full picture” before taking further action.

Labour MP for Eltham, Clive Efford, criticised Mr Malthouse for having a “wait and see attitude”, and said: “I feel like we’ve woken the minister from an afternoon nap to come in and make this statement”.

He added: “There’s a complete lack of urgency in his approach. It is quite clear that there are areas now where the Government can act; why isn’t the minister coming to this house to explain to us just exactly what he’s going to do, rather than this wait and see attitude.”

Read the details in this report by our race correspondent Nadine White:

Boris Johnson hinted at more military support for Ukraine following a call with US president Joe Biden and other allies ahead of the Nato summit on Thursday.

The prime minister also “underlined his horror” at Russia’s “use of increasingly brutal tactics in Ukraine”, including “siege warfare and targeting of civilians”, said Downing Street in a press release.

Mr Johnson, along with France’s Emmanuel Macron, Germany’s Olaf Scholz and Italy’s Mario Draghi, affirmed their “commitment to support Ukraine militarily, diplomatically and economically, equipping the democratically-elected government in Kyiv with the tools it needs to defend itself”.

The leaders also “resolved to increase the pressure on Russia to halt its unprovoked invasion, including maintaining wide-ranging and coordinated sanctions”.

Ben Wallace was quick to blame Russia shortly after he was hit by an apparent prank call last week, and now Downing Street has publicly pointed the finger at the Kremlin.

The prime minister’s official spokesperson said: “The Russian state was responsible for the hoax telephone calls made to UK ministers last week.

“This is standard practice for Russian information operations and disinformation is a tactic straight from the Kremlin playbook to try to distract from their illegal activities in Ukraine and the human rights abuses being committed there.

“We are seeing a string of distraction stories and outright lies from the Kremlin, reflecting Putin’s desperation as he seeks to hide the scale of the conflict and Russia’s failings on the battlefield.”

The government sources fear that Russia may attempt to doctor the footage obtained in the calls in a bid to embarrass the UK.

Acknowledging having spoken to imposters posing as the Ukrainian prime minister, defence secretary Ben Wallace said that “things must be going so badly for the Kremlin that they are now resorting to pranks and video fakes”.

In video released on Monday, Mr Wallace is shown speaking from Poland as the caller, purporting to be Ukrainian prime minister Denys Shmyhal, says they want to continue a “nuclear programme” to protect itself from Russia.

A Ministry of Defence source said the video was “doctored”.“What you don’t hear is the defence secretary also saying that the UK can’t have anything to do with alleged Ukrainian nuclear ambitions, because the UK is committed to the Treaty on the Non-Proliferation of Nuclear Weapons,” reported PA, citing sources.

Mr Wallace did not appear to say anything particularly embarrassing or alarming in the video, however, the full video is touted to be released in a few days.

Pranksters “Vovan and Lexus” have claimed responsibility for duping defence secretary Ben Wallace into speaking to an impostor posing as the Ukrainian prime minister.

The pair, who real names are Alexei Stolyarov and Vladimir Kuznetsov, have previously targeted Sir Elton John, a vocal opponent of Russia’s “gay propaganda” laws, Turkish president Recep Tayyip Erdogan and Canada’s prime minister Justin Trudeau.

While critics have accused the pair of having links to Russian security services, they have denied the claim.

A hoax video call with defence secretary Ben Wallace surfaced online on Monday, with Downing Street blaming Russia for orchestrating the “prank”.

Downing Street accused the Kremlin of being behind the efforts to secure sensitive or embarrassing information in duplicitous calls.

Meanwhile, officials were believed to be lobbying YouTube to remove the video of Mr Wallace, who was under the impression that he was on a call with Ukrainian prime minister Denys Shymhal.

Welcome to The Independent’s coverage of UK politics for Tuesday, 22 March 2022