Boris Johnson has admitted he does not have a worked-up plan to end the social care crisis and that a solution could be five years away.

In a BBC interview, the prime minister backtracked on his pre-election claim to have a ready-to-go rescue package – instead, saying he would be “bringing forward a proposal” later this year.

Asked for a date for action to finally be taken to improve social care, Mr Johnson said: “We will certainly do it in this parliament” – prompting the interviewer to point out: “That’s five years away.”

In July, on the steps of Downing Street, the new leader insisted he had a “clear plan we have prepared to give every older person the dignity and security they deserve”.

But the Conservative manifesto then ducked the controversy, as the Tories feared the threat of new taxes to fund a cap on costs would derail the campaign – as it did Theresa May’s in 2017.

In the interview, Mr Johnson acknowledged the NHS crisis could not be solved without “a revolution in the way we approach social care”.

He promised there would be “a plan this year” – but pledged only that his government would “get it done within this parliament”.

During the interview, Mr Johnson said the Iran nuclear agreement should be scrapped and replaced with a superior “Trump deal” – as he shrugged off being shut out of the decision to assassinate Qassem Soleimani.

Appearing to sign the death knell for Joint Comprehensive Plan of Action (JCPOA) – backed by the EU – the prime minister instead heaped praise on the US president’s negotiating skills.

Protests in Iran over downing of plane and tensions with the west Show all 23 1 /23 Protests in Iran over downing of plane and tensions with the west Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranian police officers take position while protesters gather in front of Amir Kabir University AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranians demonstrate following a tribute for the victims of the Ukraine Boeing 737 crash in front of the Amirkabir University in the capital Tehran EPA Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranian police dispersed students chanting "radical" slogans during a gathering in Tehran to honour the 176 people killed when an airliner was mistakenly shot down AFP via Getty Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University - People hold flowers as tear gas fired by police rises Online videos purported to show that Iranian security forces fired both live ammunition and tear gas to disperse demonstrators protesting against the Islamic Republic's initial denial that it shot down a Ukrainian jetliner AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranian police officers take position while protesters gather AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University AFP correspondents said hundreds of students had gathered early in the evening to pay respects to those killed in the air disaster ISNA/AFP via Getty Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranian protester prepares to throw a tear gas canister back at police AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University A protester confronts an Iranian police officer AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University epa08120223 Iranians protest to show their sympathy with victims of Ukraine International Airlines Boeing 737-800 in front of the Amir Kabir University in Tehran, Iran, 11 January 2020. Media reported that hundreds of Iranians protests in Tehran in solidarity with victims of the Ukraine plane as Iranian military released a statement claiming that Ukraine International Airlines flight PS752 was shot down due to human error. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranian police officers take position while protesters gathe AP Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University Iranians light candles for victims EPA Protests in Iran over downing of plane and tensions with the west Anti-government protest at Amirkabir University epa08120526 Iranians protest to show their sympathy to victims of Ukraine International Airlines Boeing 737-800 in front of the Amir Kabir University in Tehran, Iran, 11 January 2020. The Iranian military released a statement on 11 January 2020 that Ukraine International Airlines flight PS752 was shot down due to 'human error.' The passemger jet en route from Tehran to Kiev crashed minutes after takeoff on 08 January 2020, all all 167 passengers and nine crew members aboard were killed. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran People burn British and Israeli flags during a protest in front of the British embassy, in Tehran. Hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet EPA Protests in Iran over downing of plane and tensions with the west British embassy protestBritish embassy protest in Tehran Chanting "Death to Britain", up to 200 protesters rallied outside the mission a day after the brief arrest of British ambassador Rob Macaire AFP via Getty Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran epa08122502 Iranian hardliners shout slogans as they gather in front of the British embassy during an anti-Britain protest, in Tehran, Iran, 12 January 2020. According to reports, hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran Iranian demonstrators hold placards bearing the images of slain military commander Qasem Soleimani and Iran's Supreme Leader Ayatollah Ali Khamenei in front of the British embassy in the capital Tehran on January 12, 2020 following the British ambassador's arrest for allegedly attending an illegal demonstration. - Chanting "Death to Britain", up to 200 protesters rallied outside the mission a day after the brief arrest of British ambassador Rob Macaire at a memorial for those killed when a Ukraine airliner was shot down. (Photo by ATTA KENARE / AFP) (Photo by ATTA KENARE/AFP via Getty Images) ATTA KENARE AFP via Getty Images Protests in Iran over downing of plane and tensions with the west Protesters chant slogans and hold up posters of Gen. Qassem Soleimani while burning representations of British and Israeli flags, during a demonstration in front of the British Embassy in Tehran, Iran, Sunday, Jan. 12, 2020. A candlelight ceremony late Saturday in Tehran turned into a protest, with hundreds of people chanting against the country's leaders â€” including Supreme Leader Ayatollah Ali Khamenei â€” and police dispersing them with tear gas. Police briefly detained the British ambassador to Iran, Rob Macaire, who said he went to the Saturday vigil without knowing it would turn into a protest. (AP Photo/Ebrahim Noroozi) Ebrahim Noroozi AP Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran epa08122741 Iranian hardliners gather in front of the British embassy during an anti-Britain protest, in Tehran, Iran, 12 January 2020. According to reports, hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west A hardline protester holds up a placard during a demonstration in front of the British Embassy in Tehran, Iran, Sunday, Jan. 12, 2020. A candlelight ceremony late Saturday in Tehran turned into a protest, with hundreds of people chanting against the country's leaders â€” including Supreme Leader Ayatollah Ali Khamenei â€” and police dispersing them with tear gas. Police briefly detained the British ambassador to Iran, Rob Macaire, who said he went to the Saturday vigil without knowing it would turn into a protest. (AP Photo/Ebrahim Noroozi) Ebrahim Noroozi AP Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran epa08122743 Iranian hardliners gather in front of the British embassy during an anti-Britain protest, in Tehran, Iran, 12 January 2020. According to reports, hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran epa08122745 Iranian hardliners gather in front of the British embassy during an anti-Britain protest, in Tehran, Iran, 12 January 2020. According to reports, hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west British embassy protest in Tehran epa08122786 Iranian hardliners gather in front of the British embassy during an anti-Britain protest, in Tehran, Iran, 12 January 2020. According to reports, hundreds of Iranian hardliners gathered for a protest against Britain, a day after the UK ambassador to Iran Robert Macaire was detained after attending a a vigil for the victims of Ukraine passenger jet. EPA/ABEDIN TAHERKENAREH ABEDIN TAHERKENAREH EPA Protests in Iran over downing of plane and tensions with the west Protesters chant slogans while holding up posters of Gen. Qassem Soleimani during a demonstration in front of the British Embassy in Tehran, Iran, Sunday, Jan. 12, 2020. AP

“Let’s work together to replace the JCPOA and get the Trump deal instead, that’s the opportunity,” he said.

He also acknowledged that the chances of the US sending Anne Sacoolas back to the UK, to face justice over the death of Harry Dunn, are “very low”.

The US State Department has described the extradition request for the wife of a US intelligence official, charged with the death of the teenage motorcyclist, as unacceptable.

The prime minister told BBC Breakfast: “I think the chances of America actually responding by sending Anne Sacoolas to this country are very low. That’s not what they do.”

Put under pressure over the social care crisis, Mr Johnson said: “This is a big, big thing. I mean, this is a potentially massive change in the way we fund social care, and we’ve got to get it right.

“We have got to think very carefully about how we do it, because there are lots of quite important moral and social issues contained in it.

“You know, should taxpayers be paying for people who might be able to afford it? What is the relationship you want to encourage, should families be looking after their own, their elderly relatives (and) to what extent?