David Cameron has accused Tony Blair of not "trusting" the British people after the former prime minister lashed out at his plans for an EU referendum.

On a campaign visit to Northern Ireland, Mr Cameron hit back at suggestions he is risking the stability of the country in order to appease Ukip.

"I think Tony Blair is wrong. I want changes in Europe but then, unlike Tony Blair, I will trust the people in an in-out referendum," he said.

The Tory leader, who toured the Game Of Thrones film set in Belfast, went on: "We should ask people if they want to stay a member of this organisation.

"You cannot ignore the will of the people as Tony Blair thinks we should - and it is not just him, it is Ed Miliband."

Mr Cameron was on the second leg of a whirlwind tour visiting all four nations of the UK in a day.

He kicked off his aeroplane tour in Edinburgh, visiting the Scottish Widows headquarters for breakfast with wife Samantha.

The Prime Minister chatted to staff about pension changes as he tucked into haggis, egg and fried bread, while Mrs Cameron had a bacon roll.

He was later due to fly to Wales before addressing a rally of supporters in the south-west of England.

Ahead of the 600-mile trip, Mr Cameron insisted he had a "simple message". He said: "We have one month to save our economy from the disaster of an Ed Miliband government.

"We have one month to save Britain from his mountain of debt; one month to save Britain from his punitive taxes; one month to save Britain, and British families, from his anti-business and anti-aspiration agenda."

The premier said Britain had been put back on its feet over the past five years, adding all four parts of the UK were now growing.

But Mr Cameron could face questions about grumbles of discontent from within the Tory campaign. The Independent said the Conservative manifesto is not yet complete, less than a week before it is due to be published.

One unnamed senior Tory MP told the paper the campaign so far had been all about "narrow political advantage and tactics" rather than "passion and belief".

Speaking to reporters in Belfast, Mr Cameron said: "I am going to spend the next 30 days campaigning for and fighting for an all-out Conservative majority.

"We are only 23 seats short and I am going to spend every day between now and polling day addressing that and trying to win that, if I fall short you can ask me afterwards but I am not going to speculate on this now.

"I am going to fight for the majority that I think we can win and I think the country needs and I think the country needs because there would be a more accountable and more decisive government."

In a round of broadcast interviews, Mr Cameron said: "Tony Blair doesn't want to trust the people, doesn't think the people should have a say.

"Instead of what Tony Blair did, which was give away more money to Europe, I have safeguarded our rebate and actually cut the European budget.

"Now I'm going to get in there and reform our relationship with the EU, bringing powers back to the UK, making sure we have better control of issues like immigration. But then you, the British people, will decide in an in-out referendum."

Mr Cameron said he wanted to come to every part of the UK today to emphasise the importance of the election, and that the Tories were the only party fielding candidates in every country.

The PM refused to rule out bringing the top rate of tax down from 45p to 40p.

Asked whether he was "leaving the door open" to such a move, Mr Cameron said: "No, that is not the case. We have set out what our policies are, what our priorities are.

"That is to lift to £12,500 the basic threshold before you start paying tax - and we have said we want to lift to £50,000 the threshold before you start paying 40p rate. Those are our priorities those are our plans. We haven't got any other plans."

Mr Cameron rounded off his UK tour by speaking at a Tory rally in Wade, in the target seat of North Cornwall.

"Under this Government we are one United Kingdom and each of our four nations is growing, each of our four nations is succeeding," he said.

The Prime Minister said the party had "30 days to stick to the plan that is working".

And he heaped praise on his "team who are taking this country forward", singling out George Osborne and Home Secretary Theresa May - often tipped as possible successors to the top job.

"Who do you want in the Home Office looking after our security?" he said.

"Not (Labour spokeswoman) Yvette Cooper who always puts the left wing commentators above our intelligence services.

"Or do you want the woman who made our county safer, the woman who threw out Abu Qatada, who threw out Abu Hamza, our very own Theresa May?"

Mr Cameron also insisted the Tories could run on their record in government.

Without directly addressing figures showing waiting time targets were being missed in A&E, he told activists: "Talk about our record, all our record. And yes, talk about our record on the NHS too.

"We decided not to cut the NHS, but to put more money in every year.

"That was not a Liberal decision, that was not a Labour decision. It was a Tory decision."

Conservative candidate for North Cornwall Scott Mann, who is trying to overturn Lib Dem Dan Rogerson's 3,000 majority, was also at the rally, as were Tory ministers George Eustice and Hugo Swire.