The Conservatives are warning that immigration would soar under Labour.

The party said that net migration (immigration minus emigration) could rise from its current annual rate of about 220,000 to 840,000 people a year.

This is based on the idea that Labour want to extent the same rights to free movement that European Union citizens have to immigrants from the rest of the world.

The analysis

FactCheck asked the Conservatives to show us how they reached this “840,000 figure”. They have not yet replied.

All the press release says is that the numbers are based on “official figures and the Government’s own methodology”.

So the Conservatives’ calculations are impossible to check, but there is a more urgent problem: extending free movement to the rest of the world is not Labour party policy.

Labour conference motion

It is true that a group called Labour Campaign for Free Movement managed to get a motion passed at the party’s conference in September calling for a Labour government to “maintain and extend free movement rights”.

Campaigners from the group have told FactCheck that their ultimate aim is to extend the same rights EU migrant works enjoy to people from outside the EU.

But the phrase passed by conference “maintain and extend” is ambiguous. It could be taken to call for extending the rights already granted to EU citizens in Britain, rather than giving the same rights to the rest of the world.

The Labour party has never officially adopted the position that the phrase “extend free movement rights” means opening Britain’s borders to people from outside the EU, and party sources have been quoted today as saying that this interpretation is wrong.

Labour divided

It is fair to say that Labour appears to be split on the issue of free movement, with various senior figures sending out mixed messages today.

Shadow home secretary Diane Abbott tweeted: “The Labour Party is committed to maintaining and extending Freedom of Movement rights. But the Tories will remove those rights from the EU 3 Million. We will maintain them.

“The Tories break up families by barring spouse of British citizens, via an income requirement. Labour will scrap it, and extend Freedom of Movement rights to all those legally entitled to be here, including our own citizens among others.”

That sounds like Ms Abbott is in favour of retaining and extending freedom of movement rights for EU citizens and their families, rather than for people outside the EU.

Unite general secretary Len McCluskey said in an interview with the Guardian that he was against the conference motion becoming Labour policy, adding: “It’s wrong in my view to have any greater free movement of labour unless you get stricter labour market regulation.”

Laura Pidcock, the shadow secretary of state for employment rights, refused to be drawn on the issue in a string of broadcast interviews today.

No manifesto commitment yet

In any event, Labour haven’t put out their manifesto for the next general election yet, and there is no guarantee that a motion passed by conference will be included in it.

The contents of the manifesto will be signed off in a “clause V” meeting, attended by members of Labour’s shadow cabinet and national executive committee, as well as trade union representatives, due to be held on Saturday.

Until then, we simply don’t know what Labour’s official policy on free movement is.

The verdict

The Conservative line here is based on the idea that Labour plan to extend freedom of movement rights to non-EU citizens.

Some activists do back this position – and won a conference motion on it. But it is not Labour party policy.

We won’t find out what Labour’s real immigration policy is until the party publishes its manifesto, following a big policy meeting on Saturday.

Until we know what Labour actually plan to do, any figures the Conservatives put out on immigration are pure speculation.