With the country's two main political parties in disarray following the vote to leave the European Union, parliament's vote on renewing the Trident nuclear deterrent programme looks set to ignite divisions.

The vote, which will give approval to renew the entire 31 billion pound (37 billion euros) program, was originally scheduled to take place in March. It was delayed by then Prime Minister David Cameron until after the EU referendum. He expressed concerns that the referendum could complicate efforts to build a strong national consensus over Trident.

While he was not anticipating that Britain would vote to leave the EU, experts agree that the tumultuousness of British politics since the EU referendum could ultimately strengthen support. "In a time of increasing uncertainty and chaos - internationally and domestically - Trident is seen to be a source of stability and a guarantor of external security," Dr Simon Mabon, lecturer in international relations at Lancaster University, told DW. "While expensive to maintain, it is seen by many as the most effective military deterrent, although this fails to appreciate the changing nature of security threats in the 21st century."

Uncertain atmosphere

Conceptual work on potential designs for replacement submarines has been taking place since 2007, when MPs backed plans to renew Trident by 409 to 61 votes. In October 2010, the government decided to delay the decision on whether to proceed and how many submarines to order until 2016. At that point, the Conservatives were in coalition with the Liberal Democrats, who oppose Trident.

Given that the Conservatives won a majority in the 2015 general election and that party policy is pro-renewal, it would be a surprise if the replacement did not go ahead. This is compounded by recent events.

"The Brexit vote has created an atmosphere of uncertainty, which increases the appeal of strong national defense for people on the fence about this issue," explains Dr Matt Cole, lecturer in history at the University of Birmingham. "Floating voters in parliament might be prepared to set aside their misgivings for the time being and regard it as a broader issue. We also, of course, have had a hardening of opinion on the patriotic right and those people who were always in favor of Trident will now feel vindicated. The opposition to Trident may be somewhat muted and the support may be emboldened."

Divided Labour

The Trident vote looks set to deepen divisions within the Labour Party, currently in the throes of an acrimonious leadership challenge. Labour leader Jeremy Corbyn has been a member of the Campaign for Nuclear Disarmament since 1966. His party is divided on the question of Trident renewal; many MPs back the program. Party policy is for multilateral disarmament, though Corbyn would like to see unilateral disarmament.

"While the Conservatives are united in their support for continuing the deterrent in its current form, Labour MPs split on what is both a fundamental question of Britain's approach to defense policy, and fast becoming a litmus test for left-wing credentials among party members," Charlie Cadywould, researcher at the think-tank Demos, told DW. "While official Labour policy is still in favor of renewal, Corbyn, along with the new Shadow Defense Secretary, is firmly opposed, and will vote accordingly. For many Labour MPs on the right of the party, this is a matter of principle, but in an especially hostile climate, some will fear the prospect of retribution from grassroots groups - such as Momentum, the group founded to support Corbyn's leadership."

Corbyn faces strong opposition on this from trade union leaders, who are concerned about job losses in the event of Trident being discontinued. The nuclear defense industry is a major employer. Some estimates suggest that up to 15,000 jobs may be lost if a new batch of submarines is not commissioned.

"The vote reflects for Corbyn the need to defend his principle, particularly in the context of a situation where the nationalist right is pressing its case," says Cole. "But for his opponents this is a perfect demonstration of his being out of touch with Labour voters, and more importantly potential Labour voters, and his unwillingness to accept the policy of the party."