The prime minister was attending a NATO summit in Vilnius, Lithuania, but was asked about the situation back home by political editor Beth Rigby.

She noted that, with a series of by-elections next week, the government is trailing by 20 points in the polls and Mr Sunak's five priorities were proving tough to meet.

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These include halving inflation, growing the economy, reducing national debt, cutting NHS waiting lists and stopping boats from crossing the Channel.

Mr Sunak said: "I am absolutely laser focused on delivering for the British people. You know, their priorities are my priorities."

He added his government was trying to pass "some of the toughest legislation that any government has ever passed" when it comes to stopping small boats - which has been "opposed at every turn" by the Labour Party.

The Illegal Migration Bill, to which the prime minister was referring, will be returning to the House of Lords as part of the parliamentary ping-pong between the two houses in which amendments are voted on.

Mr Sunak added: "When I set those priorities, I didn't do it because it was easy.

"And you talk about the promises and delivery - I did it because they were the right things to focus on, and I am ambitious for the country, and I'm ambitious for what I want to achieve for people.

"So it's right that I set ambitious priorities and targets, and it's right that we strain every sinew to meet them, and that's what I'm doing."

Mr Sunak's pledge to bring down inflation by half - made in January - means it would need to fall to around 5% by the end of the year.

It is currently stuck at 8.7%, and the Organisation for Economic Co-operation and Development (OECD) reckons it will average out to 6.9% over the course of 2023.

The OECD also reckons the UK economy will grow by 0.3% this year, and 1% in 2024.

On the third pledge, UK government debt has now surpassed gross domestic product for the first time in 62 years.

For the NHS, Mr Sunak has claimed that waiting lists are falling, but there is some dispute depending on which figures are used.

For example, according to Full Fact, the number of patients waiting for more than 18 months has fallen recently.

However, the number of people waiting to see a consultant reached a high of 7.42 million in April.

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And health minister Maria Caulfield admitted that numbers will go up before they go down.

Mr Sunak said in May that waiting lists "should be coming down" by spring next year.

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On stopping the boats, the number of people who have arrived across the Channel is only just behind the number at the equivalent time last year.

So far, 13,144 people have arrived in the UK on small boats this year.