Two left-wing groups have criticised Labour for its stance on free movement and Brexit.

Having ruled out blocking Article 50 in Parliament, the party is on board with Britain leaving the European Union, and on “hard Brexit” style terms.

The shadow chancellor John McDonnell spoke of “enormous opportunities” presented by Brexit, and called on Remainers to be “more positive” about the outcome of the referendum. The shadow business secretary Clive Lewis also doubled down on backing Brexit this week by saying free movement “hasn’t worked” for millions of Britons.

This has angered activists in the left-wing alternative Remain group, Another Europe Is Possible, who issued statements criticising Labour’s direction.

“What is the point of our MPs having the right to vote on Article 50 if they do not use it to extract concessions against hard Brexit?” asked national organiser Michael Chessum. “Labour must champion the progressive elements of EU membership: free movement, workers’ rights, the environment and human rights. Doing this is not about betraying the will of the people.”

The group’s convenor Luke Cooper added: “Labour’s job is to work with other progressives to use every democratic means to stop a ‘hard Brexit’ and stand up to the rising tide of anti-immigrant populism.”

Left Unity, a fringe left-wing party and brainchild of Ken Loach, has also condemned the opposition’s stance. Its principal speaker Joseph Healy commented: “Freedom of movement is one of the EU’s most progressive policies, allowing workers to move freely throughout the Union . . . To retreat now into a Little England position is shameful and indicates both a failure of nerve about alienating Brexit voters and a failure of vision. There is no international working class solidarity in these Labour policies.”

What’s interesting is that Left Unity was pretty on board with Labour when Jeremy Corbyn took charge. It voted not to stand candidates against Labour in parliamentary elections, and also to support the network that grew out of his campaign, Momentum. It lost several hundred members to Labour following Corbyn’s election, but seemed happy to come onside – having criticised Ed Miliband’s leadership since it was founded in 2013.

Similarly, Another Europe Is Possible has not hitherto been hostile towards Corbyn, and praised his speeches during the referendum campaign. And its national organiser Chessum is a member of Momentum’s steering committee.

It’s unsurprising that left-wing groups are defending free movement. But these interventions are the first real sign of the alternative left distancing themselves from a party they hoped would reflect their values under Corbyn.