United Kingdom

new "socialist alternative" before next election

An ever-expanding category, that.

https://en.wikipedia.org/wiki/Category:Socialist_parties_in_the_United_Kingdom

https://en.wikipedia.org/wiki/Cross-Community_Labour_Alternative

Cross-Community Labour Alternative is a minor political party founded to contest the 2016 Northern Ireland Assembly election. It stood three candidates[3] in the East Belfast, South Belfast and East Antrim constituencies. It was initiated by the Socialist Party.[4]

https://en.wikipedia.org/wiki/Socialist_Party_(Ireland)

The Socialist Party (Irish: Páirtí Sóisialach) is a political party in Ireland, active in both the Republic of Ireland and Northern Ireland. Internationally, it was affiliated to the Trotskyist International Socialist Alternative (previously the Committee for a Workers International) until 2024.

https://en.wikipedia.org/wiki/Left_Unity_(UK)

Left Unity is a left-wing political party in the United Kingdom founded in 2013 when film director and social campaigner Ken Loach appealed for a new party to replace the Labour Party (which according to him failed to oppose the United Kingdom government austerity programme and had shifted towards neoliberalism).[5][6][7] More than 10,000 people supported Loach's appeal.[8]

https://en.wikipedia.org/wiki/Progressive_Unionist_Party

The Progressive Unionist Party (PUP) is a minor unionist[6] political party in Northern Ireland. It was formed from the Independent Unionist Group operating in the Shankill area of Belfast, becoming the PUP in 1979. Linked to the Ulster Volunteer Force (UVF) and Red Hand Commando (RHC), for a time it described itself as "the only left of centre unionist party" in Northern Ireland, with its main support base in the loyalist working class communities of Belfast.[7]

https://en.wikipedia.org/wiki/Social_Justice_Party_(UK)

The Social Justice Party (SJP) is a left-wing minor political party in the United Kingdom.[2] It was launched in August 2023 at a conference in Whitby,[2] and was officially registered with the Electoral Commission on 2 February 2024.[3][4]

https://en.wikipedia.org/wiki/Transform_(political_party)

The Transform Party (also known as Transform Politics, or simply Transform) is a political party active in Great Britain. A merger of two political groups, the Breakthrough Party and the People's Alliance of the Left, Transform aims to build a new left-wing political party to challenge both the Conservative Party and the Labour Party. The party is also associated with the Liverpool Community Independents and Left Unity, who remain independent parties.[1][2]

https://en.wikipedia.org/wiki/Workers_Party_of_Britain

The Workers Party of Britain (WPB), also called the Workers Party of Great Britain (WPGB) or Workers Party GB,[16][17][18] is a socialist and socially conservative political party in the United Kingdom, strongly identified with its leader, former Labour and Respect MP George Galloway.

https://en.wikipedia.org/wiki/Socialist_Labour_Party_(UK)

The Socialist Labour Party (SLP) is a socialist political party in the United Kingdom. The party was established in 1996 and was led by Arthur Scargill, a former Labour Party member and the former leader of the National Union of Mineworkers. The party's name highlights its commitment to socialism and acknowledges Clause IV of the Labour Party's former constitution, as fundamental to the party's identity. As of 2024, it is led by Jim McDaid.[1]

https://en.wikipedia.org/wiki/Socialist_Party_of_Great_Britain

The Socialist Party of Great Britain (SPGB) is a small socialist political party in the United Kingdom. Founded in 1904[2] as a split from the Social Democratic Federation (SDF), it advocates using the ballot box for revolutionary purposes and opposes both Leninism and reformism. It holds that countries which claimed to have established socialism had only established "state capitalism" and was one of the first to describe the Soviet Union as state capitalist. The party's political position has been described as a form of impossibilism.