The International Development Secretary was forced out after it emerged she held a series of secret meetings with Israeli officials while on a private holiday – actions Ms Patel admitted “fell below the high standards” expected of her position.
Her departure comes just a week after Defence Secretary Sir Michael Fallon tendered his resignation following allegations about his behaviour towards women.
And as the dust settles following the second high profile departure in successive weeks, the embattled Mrs May will be weighing up a list of potential replacements to head of the Department for International Development.
Ms Patel was a leading Leave campaigner, and there are calls from some some Brexiteers that her Cabinet position should be filled with a like-minded MP.
Priti Patel replacement: Contenders Sir Alan Duncan, Penny Mordaunt and Rory Stewart
I accept that in meeting with organisations and politicians during a private holiday in Israel my actions fell below the high standards that are expected
But others, including prominent Brexit-backer Jacob Rees-Mogg, say her replacement does not necessarily have to have supported Leave before the referendum, as long as they now accept the UK is leaving the EU.
Potential contenders for the newly-vacated Government position include:
– Oxford alumni Sir Alan Duncan, who currently serves as Boris Johnson’s deputy in the Foreign Office.
Sir Alan attended the prestigious university at the same time as the PM and was president of the Oxford Union before her husband Philip.
The 60-year-old has worked as a minister in the Department for International Development before, but his support for Remain during the referendum could anger Brexiteers.
Sir Alan Duncan
Ms Mordaunt worked as an aid worker in post-revolutionary Romania and has quickly risen through the Tory ranks since her election as MP for Portsmouth North in 2010.
She had been touted as a contender for the Defence Secretary job because of her previous experience as Minister of State for the Armed Forces.
Penny Mordaunt supports Brexit and has experience in foreign aid
He now serves as a joint DFID and Foreign Office minister.
His diplomatic career took him to Iraq, where he became deputy governor of two provinces following the 2003 invasion.
Rory Stewart backed Remain, but his varied and extensive experience could make him a good candidate
Her current role as Minister of State in the Department for Education could give her the experience needed for a Cabinet job.
The MP for Guildford did not publicly disclose which side she supported during the EU referendum.
– Alistair Burt, whose long ministerial career began under John Major.
He currently serves as a joint DFID and Foreign Office minister and backed Remain during the referendum.
Anne Milton and Alistair Burt have been touted as potential replacements for Ms Patel
Ms Patel’s resignation came last night after she was summoned back to Downing Street from an official trip to Africa.
Earlier this week it emerged the Withal MP had attended 12 meetings with senior figures in Israel – including Prime Minister Benjamin Netanyahu – while on holiday in the country in August.
The meetings were held without other UK officials present and related to sensitive areas of British foreign policy.
In her resignation letter, Ms Patel said: “I accept that in meeting with organisations and politicians during a private holiday in Israel my actions fell below the high standards that are expected of a Secretary of State.”
Priti Patel leaving Downing Street after handing in her resignation
Responding to her resignation, the Prime Minister said: “As you know, the UK and Israel are close allies, and it is right that we should work closely together.
“But that must be done formally, and through official channels.
“That is why, when we met on Monday, I was glad to accept your apology and welcomed your clarification about the trip to Israel over the summer.
“Now that further details have come to light, it is right that you have decided to resign and adhere to the high standards of transparency and openness that you have advocated.”