The party's primary aim is the following: ... unite the diverse strands of radical and socialist politics in the UK including workers' organisations and trade unions; ordinary people, grass root organisations and co-operatives rooted in our neighbourhoods and communities; individuals and communities facing poverty, discrimination and social oppression because of gender, ethnicity, age, disability, sexuality, unemployment or under-employment; environmental and green campaigners; campaigners for freedom and democracy; all those who seek to authentically voice and represent the interests of ordinary working people.Left Unity was founded by Ken Loach, who believed that there was an "absence of a strong voice on the left" and that "the Greens are alone among the political parties in not standing up for the interests of big business".

The party advocates common ownership and democratic control of "the means of producing wealth" and the reversal of what it sees as 30 years of neoliberalism, aiming to "build international networks of solidarity to support any government introducing such measures within Europe and elsewhere".

[15] It supports full employment "through measures such as reduced working hours for all; spending on public housing, infrastructure and services; and the public ownership of, and democratic collective control over, basic utilities, transport systems and the financial sector" and opposes "the casualization of employment conditions and laws which restrict the right of workers to organise effectively and take industrial action".

[13] The party has been criticised by far-left political organisations who say that the party has a "commitment to govern within the framework of capitalism" and its economic programme "is a left-Keynesian, reformist programme, which would leave more than half of the FTSE 100 companies still in private hands, despite phrases in it about a "strategic vision of structural change" and the principle "from each according to their ability, to each according to their needs", lifted from the Communist Manifesto".

[17] The 2015 pre-general election Left Unity manifesto appears instead to pursue a more far-left line and refers to the needs for an economy "run democratically, not controlled by the few in the interests of 1% of the population.

[18] According to Loach, the party supports a £10 minimum wage[update] and wishes to emulate "the kind of economy that Syriza in Greece and Podemos in Spain are calling for".

Left Unity would reintroduce rent controls and security of tenure, using compulsory purchase powers to take over empty homes and end the criminalisation of squatting.

When the politicians propose using market mechanisms to limit carbon emissions, it is clear that they cannot see a more democratic or sane way out of the climate crisis.

Speeches deemed as supporting male privilege have been received negatively and it is claimed that "Left Unity is set to be a self-consciously feminist organisation".

[23] Left Unity is opposed to xenophobia[24] and Luke Cooper of the Anticapitalist Initiative introduced socialist policies on immigration and racism.

Immigration controls divide and weaken the working class and [are] therefore against the interests of all workers.The party overwhelmingly voted in favour of this policy.

[28] Thus the party described the vote to leave the EU as "a disastrous outcome", saying the following: We deeply regret that the working people of Britain have been deceived and manipulated into believing that Brexit will bring about relief from the grinding austerity that is destroying lives and communities.

We will fight to defend the rights of working class communities and rebuild support for socialist ideas.The party "stands in solidarity with the Palestinian people in their struggle against oppression and dispossession".

[30] In 2014, Left Unity was criticised by media outlets worldwide after a motion that called ISIS a "stabilising force" with "progressive potential" was proposed by two members at the party's annual conference.

[34] According to the International Socialist Network's Autumn 2014 Discussion Bulletin, it was then part of Left Unity[35] with members elected to the party's national council.

[48][49] Accompanying Corbyn's campaign and unexpected election was a significant influx of several hundred thousand of new members and supporters, shifting the political direction and membership base of the party leftwards.