Labour Left Alliance (LLA)
The LLA is a left grassroots British Labour Party network. Who is currently building a democratic, transparent and socialist Labour Left. The primary document to join and support can be found here. Once you have signed the appeal you can also join their Facebook pages.
Left Unity was founded in 2013, because the main parties then all supported the policies they call ‘austerity’: deep cuts in public spending designed to destroy the social and economic gains working people have made over many decades. It’s possible that the Labour Party, under Jeremy Corbyn, may reverse some of this if in government, but that’s not certain. Left Unity remains a political formation to work for socialist policies and against the austerity agenda of governments. Their site can be found here.