PRESSURE was mounting on Theresa May last night following the “humiliating” resignation of international development secretary Priti Patel.

Opponents labelled the event a “global shambles” following days of controversy over Ms Patel’s secret meetings with political figures in Israel.

Labour deputy leader Tom Watson published a letter asking the Prime Minister to clarify what she knew and when she knew it.

He said he had been told Ms Patel met officials from the British Consulate General Jerusalem while in Israel – but that this had not been made public.

He continued: “If this were the case, then it would surely be impossible to sustain the claim that the Foreign and Commonwealth Office was not aware of Ms Patel’s presence in Israel.

“The existence of such a meeting or meetings would call into question the official account of Ms Patel’s behaviour, and the purpose of her visit.”

He set out a series of questions to the Prime Minister, including whether Mrs May knew of any meetings and whether she or the Foreign and Commonwealth Office had requested information be “suppressed”.

Mr Watson said he was “pleased” Ms Patel had resigned, as “this was as clear a breach of the ministerial code, and of diplomatic protocol, as can be imagined, and the only surprise about her resignation is that it came so late”.

Liberal Democrat deputy leader Jo Swinson also insisted Number 10 had questions to answer “about their complicity in this scandal”.

She said Ms Patel had “rightly been forced to step down for her cover up of meetings with foreign officials and the inappropriate requests for aid to be sent to the Israeli military in the Golan Heights”.

She added: “This was an appalling error of judgement and is nothing short of a major failure by the British government.

“Number 10 must answer questions about their complicity in this scandal. Someone has been deceived, either the British people or the Prime Minister’s office. Whichever it is someone must be held to account.”

Meanwhile, the SNP’s Westminster leader Ian Blackford used the resignation to call on Foreign Secretary Boris Johnson to follow suit.

He said: "This has been utterly humiliating for the Prime Minister. Theresa May couldn't manage a resignation without making a global shambles of it.

"Priti Patel's resignation doesn't solve the chaos of the cabinet and now the Prime Minister must turn her attention to Boris Johnson, whose incompetence this week - and refusal to apologise - has had potentially tragic consequences for British-Iranian Nazanin Zaghari-Ratcliffe, who is incarcerated in Tehran.

"If this Prime Minister is intent on holding on to any credibility, her Foreign Secretary must be next to go."

Figures from across the political spectrum took to social media to lambast the Government.

Labour stalwart John Prescott wrote: “When you can't even sack a minister who lied to you, you've got to ask what's the point in being Prime Minister?”

Labour MP Alex Cunningham tweeted: “Amazed the PM waited for disgraced Priti Patel to resign after her secret meetings with Israelis – if she wasn’t so weak and wobbly she’d have sacked her earlier in the week.”

And former political strategist Alastair Campbell wrote: “I’d like to think if I had all those hours on a plane I could have written a better resignation letter than that.”

But Boris Johnson paid tribute to his colleague and insisted she had a “great future” ahead.

He said: “Priti Patel has been a very good colleague and friend for a long time and a first class secretary of state.

“It’s been a real pleasure working with her and I’m sure she has a great future ahead of her.”

Former UKIP leader Nigel Farage said Ms Patel’s resignation was “very sad”, adding: “She’s a good woman and a leading Brexiteer in the cabinet.”

Last night, honorary president of the Conservative Friends for Israel lobbying group Lord Polak – who had joined Ms Patel in many of her secret meetings – avoided questions from journalists.