Former prime minister Theresa May has admitted in a documentary that she should have met Grenfell Tower survivors sooner after the 2017 fire.

Mrs May, who is standing down from Parliament at the election, also said she took responsibility for the Home Office’s hostile environment policies on immigration while she was Home Secretary.

The outgoing MP for Maidenhead described Donald Trump as an “unpredictable” president, adding that “unpredictability is difficult to deal with”.

Speaking during an ITV documentary on her 2016-2019 premiership, Mrs May said of initially not meeting survivors of the June 14 2017 blaze that claimed 72 lives: “I should have gone and met victims. I recognise that.”

Her chief of staff, Gavin Barwell, told Theresa May: The Accidental Prime Minister, which will air on ITV1 at 10.25pm on Monday, that her team “got that call badly wrong”.

He added: “We served her very badly because it played on the perceptions that people already have from the election campaign, that she wasn’t comfortable with that kind of face-to-face contact.”

Discussing those caught up in the Windrush scandal, which followed her hostile environment policies while home secretary, Mrs May said: “Should we in the Home Office have had a greater sense of trying to identify whether there were other people, people who were going to get caught up in this way?

“I don’t believe that question was ever asked. And that’s what lay behind the problems.”

Asked if she was home secretary when this was the case, she said: “I was. And as home secretary, you take responsibility.”

Mrs May, who served as David Cameron’s home secretary between 2010 and 2016, also admitted that sending out vans with “Go home or face arrest” written on them as part of a Home Office advertising campaign in 2013 targeting illegal immigrants was “wrong”.

Ms May said: “It was wrong, and we stopped it. We realised after a short period of time that we needed to stop that.”

During the documentary, directed by Sam Collyns, Mrs May recounted the time Mr Trump took her hand while they walked outside the White House in 2017.

She said: “We literally were just walking along and he said, ‘There’s a little slope around the corner. Take care.’

“And I thought, well, it’s fine. My heels are not that high. I’ll be fine.

“And next thing I knew, he was holding my hand as we walked up, and of course, I wasn’t able to reclaim my hand before we got the television cameras of the world upon us.”

Mr Barwell said the “most disheartening conversation” with the former president was over the 2018 poisoning of Sergei and Yulia Skripal in Salisbury, adding: “His initial reaction was, well, why should I do anything?”

In the documentary, Penny Mordaunt said she was told that a key part of Mrs May’s Brexit deal was already set in stone after being agreed with former German chancellor Angela Merkel before Cabinet went to Chequers in 2018 to discuss it.

Asked if she felt politically-damaging resignations from her Cabinet over Brexit were a betrayal, Mrs May said: “Politics is politics. People had a different view.

“They, I think there were many Brexiteers who, not to put too fine a point on it, didn’t like a Remainer being in charge of Brexit.”

Mrs May said comments made by her 2016 Conservative leadership election rival Dame Andrea Leadsom that being a mother made her a better candidate in comparison to the then-home secretary were “unfortunate”.

Former chancellor Sir Sajid Javid told the documentary that Mrs May’s 2017 election campaign, which attempted to highlight her “strong and stable” leadership, was “a total disaster from day one” – with the Conservatives ultimately losing their small overall majority at the polls.

Amber Rudd, Mrs May’s initial home secretary, said her reputation had been enhanced in comparison to the conduct of subsequent prime ministers.

Ms Rudd said: “Given what’s followed, her reputation is enhanced.

“I didn’t know at the time that truth and decency wasn’t always going to be part of a prime minister’s make-up.”

Former home secretary Suella Braverman told the documentary: “I think history will remember Theresa as a dedicated public servant – who was probably in the wrong job at the wrong time.”