Veteran British socialist Jeremy Corbyn called for his new political party to "come together" as he opened its inaugural conference yesterday, as it seeks to move on from a messy launch and become a viable left-wing challenger to Labour.

As British politics fractures into a multi-party system and Prime Minister Keir Starmer takes Labour rightward on some issues, Corbyn's outfit hopes to fill a gap on the left.

"We're here today to do something dramatic...to found a new Democratic Socialist Party in Britain that can challenge power in our society," Corbyn told the conference in the northwestern English city of Liverpool.

But the ex-Labour leader acknowledged the new party needs to get past its internal differences.

"As a party, we've got to come together and be united because division and disunity will not serve the interests of the people that we want to represent," he said.

The appeal for unity comes after a rocky start for "Your Party", which Corbyn and fellow ex-Labour lawmaker Zarah Sultana announced they were forming in July.