UK Labour has insisted it still supports the retention of Britain’s Trident nuclear weapon system after Jeremy Corbyn appeared to throw it into doubt.

The Labour leader said he would order an immediate strategic defence review covering “all aspects” of defence policy if he won the General Election on June 8.

In a statement issued following his appearance on BBC1’s The Andrew Marr Show, a party spokesman said: “The decision to renew Trident has been taken and Labour supports that.”

In his interview, Corbyn – a life-long supporter of unilateral nuclear disarmament – declined to say whether the party still backed Trident.

Asked whether it could be cancelled under Labour, he said: “We will have a strategic defence review immediately which will include all aspects of defence. We would then look at the situation at that time.”

Pressed on whether it would be in Labour’s election manifesto, he said: “We haven’t completed work on the manifesto yet. We are having that discussion in the Labour Party and we will produce our manifesto early in May.”

Corbyn’s comments threatened to reopen bitter divisions within the party. He was last year forced to abandon his attempts to persuade it to back his unilateralist position in the face of opposition from the trade unions. But while at odds with his parliamentary party, Corbyn’s anti-Trident stance is consistent with Scottish Labour’s. The SNP and Scottish Greens are also opposed to renewal of the £100 billion system, which they say is outdated at a time when terrorism from groups such as Daesh is a key threat.

Corbyn will today make his first visit to Scotland in the 2017 General Election campaign, to speak at the Scottish Trades Union Congress (STUC) in Aviemore outlining Labour’s offering to Scots.

His party suffered its worst General Election result north of the Border in May 2015 when it lost 40 of its 41 seats, and now pressure in on to retain its only MP, Ian Murray in Edinburgh South.

Corbyn's promises will include protect pensions of a million Scots by guaranteeing the Triple Lock; giving almost half a million Scottish workers a pay rise with a £10 per hour real living wage; and negotiating a Brexit deal to protect working people.

He will also promise to repeal the Trade Union Act and open inquiries into firms' blacklisting of trade union representatives.

“Labour will challenge the rigged system that is holding our country back," he is due to tell the meeting. "And just like trade unions, we will stand for the many not the few."

“Labour will never, ever apologise for the closeness of our relationship with the trade union movement – you are our family.

“That is why one of the very first things we will do when forming our Labour Government will be to repeal the vicious Tory Trade Union Act. Giving working people the rights to collectively organise and make their lives better, safer and more content.

“We will open inquiries into blacklisting and Orgreave. And we urge the Scottish Government to set up an inquiry into the actions of the Scottish police during the miners’ strike. We will make jobs better and more secure with a real living wage of £10 an hour by 2020 and stronger rights at work.

“We will end the public-sector pay cap that disrespects our committed public servants every day.

“We will end the need for food banks.

“We will upgrade our economy to create wealth for all through investment in our infrastructure, helping our small businesses, delivering high-skill jobs and ending poverty pay.”

A YouGov poll for yesterday’s Sunday Times gave May a lead of 23 points over Labour – 48 per cent to 25 per cent – putting the Tories on course for a three-figure majority.

According to the same poll, Murray would lose his Edinburgh South seat to the Conservatives.

Ahead of his visit to Scotland, Corbyn announced he would seek to create four new UK-wide bank holidays on the patron saint’s day of each of the home nations if he became Prime Minister.

He said the move would bring together England, Scotland, Wales and Northern Ireland, while giving workers a well-deserved break.

Under the plan, there would be public holidays on St David’s Day (March 1), St Patrick’s Day (March 17), St George’s Day (April 23) and St Andrew’s Day (November 30).