David Cameron's patriotic credentials came under Ukip scrutiny, just hours before the pro-EU prime minister clashes with Nigel Farage in a live TV event on the EU referendum. The Ukip leader unveiled a poster with the caption 'I want what's best for the EU' next to a picture of Cameron, while Farage had the words "I want what's best for Britain" next to his face.

The attack advertisement was launched in Westminster prior to ITV's hour-long 'Cameron and Farage Live' show from 9pm BST, which will see the politicians take questions from a studio audience.

The Conservative leader also made another intervention in the EU referendum on 7 June, after calling a rare press conference. The prime minister accused Vote Leave of "resorting to untruths".

"It is irresponsible. It is wrong. It is time that the Leave campaign was called out on the nonsense that they are peddling," Cameron declared.

"So as you make up your mind in this referendum, and you wonder – what does this all really mean for me? What does free trade and the Single Market and business investment and stability mean? How relevant is it to my life?

"Let me tell you. It matters for your job. It matters for the prices that you pay in the supermarket each week. It matters for the mortgage you pay, or your chances of getting on the housing ladder. It matters for your pension. It matters for the price of your family holiday. It matters for the money that we have available to spend on your local hospital or your local school."

The PM also denied that he was losing the EU referendum debate, as recent opinion polls show a shift towards Leave with just over a fortnight to go before the 23 June ballot.

Vote Leave responded to Cameron's press conference by claiming the Remain campaign and Number 10 had gone into a "blind panic". Ukip MP Douglas Carswell said: "David Cameron's renegotiation was a failure − no-one believes he got a deal worth the paper it was written on.

"Now people are rejecting his campaign of fear. The prime minister says we need a proper debate about the facts but he is too chicken to take on anyone from the Vote Leave campaign head-to-head.

"David Cameron and George Osborne have both admitted that they have given up our right to veto future EU treaties, that the EU has ignored us in the past over bailouts and they know their guarantees on the renegotiation are about as trustworthy as their mate Nick Clegg's pledges on tuition fees."