The defection of seven politicians from the UK’s left-wing Labour party on February 18 could strengthen British Prime Minister Theresa May, and may even help her Brexit deal.

As reported by the Reuters news agency, the seven Labour separatists, who call themselves The Independent Group, will need a lot of support if they are to gain any traction. The new group could potentially attract other lawmakers from Labour, disillusioned Conservatives, and even soak up the remnants of the centrist Liberal Democrats. It could then form a blocking group in parliament.

However, potential rebels will be deterred by the UK’s winner-takes-all electoral system, which tends to leave smaller parties under-represented in parliament.

In a separate report, the Associated Press (AP) noted that this is the latest fallout from Britain’s decision to leave the European Union, which has split both of the country’s two main parties – Conservatives and Labour – into pro-Brexit and pro-EU camps.

Many Labour lawmakers have been unhappy with the party’s direction under leader Jeremy Corbyn, a veteran socialist who took charge in 2015 with strong grass-roots backing. They accuse Corbyn of mounting a weak opposition to Conservative Prime Minister Theresa May’s plans for leaving the EU, and of failing to stamp out a vein of anti-Semitism in the party.

Luciana Berger, one of those who quit Monday, said Labour had become “institutionally anti-Semitic.”

“I am leaving behind a culture of bullying, bigotry and intimidation,” she said at a news conference alongside six colleagues.

In turn, Corbyn said he was “disappointed that these MPs have felt unable to continue to work together for the Labour policies that inspired millions at the last election and saw us increase our vote by the largest share since 1945.”

As quoted by AP, Victoria Honeyman, a lecturer in politics at the University of Leeds, said history suggests the breakaway group will struggle to gain traction in British politics.

“It’s very cold out there as an independent,” she said. “It’s all well and good leaving because you believe the party has moved away from you, but you can often achieve more from being inside the tent.”