Two contenders for No 10 - Jeremy Hunt and Tom Tugendhat - back legislation to make changes to Northern Ireland Protocol

He told LBC: “The Northern Ireland Protocol has to change and that’s why I supported this bill.

“I hope that with somebody who wasn’t Boris Johnson in No 10 the mood music of our relations with the EU would change and we could legally negotiate some proper changes to the protocol.

“I think we have to be very clear with the EU that no British prime minister could allow a situation where we don’t have an internal market, where businesses from England can export freely to businesses in Northern Ireland.”

Mr Hunt also said that he would not axe the high speed rail line in England, HS2. He said he would “keep that going”.

Meanwhile, Tom Tugendhat, another leadership candidate, when asked if he would continue to support the Protocol Bill, said: “I will be continuing to support all the uses of leverage that I can to make sure that the United Kingdom as an entire, whole unit remains sovereign and intact.

“I will also be negotiating with those in Dublin and those in Brussels to make sure that what we do is we don’t need to use its provisions, and what we actually get to is the negotiated, trust based agreements that I think are a heartbeat away – if we can get a clean start, and a return to service of this government, in Westminster, the government in Northern Ireland, the government in Dublin, and a return to service by the Conservative Party too.”

On the ‘Sunday Politics’ on BBC NI, he said: “I think it’s absolutely essential that what we do is get the changes to the relationship between Northern Ireland and Great Britain that deliver the connections that all of us need, but also that defend the important connections North-South.

“We know very well that North-South, East-West, whichever way you’re trading, it needs it to work and we need to make sure that Northern Ireland remains the best place to do business and the strongest economy it could be.”

Mr Tugendhat added: “I think defending the sovereign integrity of the United Kingdom is exactly what any prime minister in Westminster would do and should do. What I’m talking about is building up trust between partners and allies.”

When he was asked it he really thought he was a serious contender for the top job, he replied: “I am absolutely serious. I think we need to get back to serving the British people – the British people across all of these islands, the people of the United Kingdom in Northern Ireland, and of course across England, Scotland and Wales.

“I think this is an opportunity for a clean start, and an opportunity for all of us to get back to what we need to be doing which is governing in the interests of the British people.

“As you may know, one of my very closest and oldest friends in politics is Doug Beattie who leads the Ulster Unionists but I also served in the Army alongside Jeffrey Donaldson’s brother.

“So these are two leaders in Northern Ireland who I know extremely well. I have also, as you may know, been to Dublin on many occasions and have got very good relationships with the government in Dublin. When you talk to people in Dublin or in Brussels or in Northern Ireland, many of the ideas are very similar. Many of the things that people are talking about, whether you’re in the Ulster Unionists, the Democratic Unionists or even the Alliance and some in the SDLP – they talk about changing the protocol, they talk about the changes we need.”

Mr Tugendhat added: “And that’s exactly what I’d be delivering because what we need is an economy in Northern Ireland that works for the people of Northern Ireland but also has the complete connection with Great Britain – that connection across the United Kingdom – and keeps the island of Ireland as an economic entity.”

Asked if he would be a leader for “Jeffrey Donaldson and Doug Beattie” alone, Mr Tugendhat said: “As someone whose great grandparents came from Limerick I can tell you that I would be a leader for the whole community.”