Cabinet ministers place more importance on the next Tory leadership contest than Brexit, Sir Keir Starmer has claimed, in a swipe at the Foreign Secretary’s warning that a customs union would not be a “long-term solution”.

The shadow Brexit secretary said Jeremy Hunt’s comments provided “yet more evidence” that many in the Cabinet believe the “most important thing right now” is the race to be Theresa May’s successor.

Sir Keir made the remarks in response to an interview in which Mr Hunt said he had “never believed” that a customs union is a “long-term solution”.

The Labour frontbencher tweeted: “This is yet more evidence that for many in the Cabinet the most important thing right now is the next Tory leadership contest.”

As discussions continue between the Government and the Labour Party, the Foreign Secretary said it was still possible that the UK would not have to take part in the European elections in three weeks’ time.

He warned that the outcome would not be “pretty” for both parties if they had to participate in the polls and said the cross-party talks could yield a deal in the next week.

Foreign Secretary Jeremy Hunt visits Kibera in western Nairobi. Credit: Harriet Line/PA

Speaking in Nairobi, Kenya, on the last leg of his week-long African visit, Mr Hunt said there would need to be a “very high degree of statesmanship on both sides” in the discussions.

“We have an adversarial system in Westminster and it’s in our DNA not to co-operate with each other.

“But I think the glimmer of hope we have in this situation is that both Conservative core voters and Labour core voters want Brexit sorted, and both would be extremely angry with the party they voted for if we had another general election without Brexit being delivered.”

He added: “This is a very exceptional time and there are substantively difficult issues, but I don’t think it’s impossible.”

Theresa May hopes for constructive talks with Labour next week. Credit: PA

Asked if he would support a customs union compromise as part of the discussions, Mr Hunt said: “I’ve never believed that a customs union is a long-term solution because how could you expect the EU, for example, to stand up for the rights of Scotch whisky distillers if they were negotiating a trade deal with the United States or Japan, even though the UK had absolutely no say in that trade deal?

“There’s no example anywhere in the world where a large economy like the UK – the fifth largest in the world – subcontracts the negotiation of its trade deals.

“But I think that what Labour really want when they talk about a customs union is the benefits of a customs union: friction-less trade, to facilitate issues around the border in Northern Ireland and manufacture and supply chains, and we want that too.

“So, if we can find a solution that delivers the benefits of the customs union without signing up to the current arrangements, then I think there will be potential.”

Jeremy Hunt speaking alongside Kenyan foreign minister Monica Juma at a press conference in Nairobi. Credit: Harriet Line/PA

He said that while he supported the Prime Minister’s deal, there may be things that can be done to make it “more acceptable” to Labour without compromising on the “things that we think are essential”.

Elsewhere, Environment Secretary Michael Gove issued a renewed plea for MPs to back Mrs May’s deal.

In a speech to the Scottish Conservatives conference, Mr Gove said: “It enables us to leave the EU while safeguarding essential interests and liberating us to enjoy new opportunities.”