When David Cameron promised last week that he would have “one last go” at securing curbs on immigration from within the European Union, he knew his rhetoric stood little chance of success. Days later, the President of the European Commission Jose Manuel Barroso confirmed there was “no possibility” the Prime Minister’s plans could succeed, that “it is not up for negotiation”.

For all of Cameron’s promises regarding his ‘renegotiation’ of Britain’s relationship with Europe, the obstinate reality of Barroso and the EU blob is clear: free movement is non-negotiable. This has an important consequence for how politics is being conducted in this country. It means the debate on immigration in Britain is fundamentally dishonest.

Going into next year’s election, the Conservative Party is trying to convince voters that, if you vote for them, they will limit migration from Europe. Labour’s position is not dissimilar. Ed Miliband has said immigration must be “properly managed”, and the Shadow Home Secretary Yvette Cooper has admitted “the pace and scale of immigration” under the last Labour government “was too great and it is right to bring it down”. “We’ve listened and learned,” she says, in other words, wink wink, nudge nudge, Labour will limit European immigration.

Both of these positions are deeply disingenuous. The truth of the matter, as Barroso told us this weekend, is that while Britain remains a member of the EU, Brussels will not allow this country to withdraw from the freedom of movement principle that will always be a prerequisite of membership. Since both the Conservative and Labour leaderships want to stay in the EU, they cannot deliver on their promises to the electorate. Put simply, they are lying.

To be fair to UKIP, only Nigel Farage’s party has a relatively consistent position on immigration. UKIP wants to leave the EU, then once that is achieved it will begin to control European immigration. This is clearly a more honest position than that of Labour and the Tories.

However, UKIP too are not being truthful with voters. The party’s billboard campaign earlier this year claimed “British workers are hit hard by unlimited cheap labour”, despite government analysis finding “little evidence… of a statistically significant impact from EU migration on native employment outcomes”.

UKIP’s Economics spokesperson Patrick O’Flynn alleges “unlimited EU immigration is to blame for stagnant wages”. Again, the evidence shows the impact is minimal. UKIP also tells us the country is “full”. In truth Britain is far less densely populated than many developed nations.

Of course, much of UKIP’s argument on immigration is cultural rather than economic, so is more a matter of opinion than facts and figures. But when they talk about the economic impact of immigration, UKIP, as with Labour and the Tories, are not being honest.

In UKIP, British voters have a party that has a coherent plan on how it wants to reduce European immigration, but one whose economic arguments are weak. In the Conservatives and Labour, voters have two parties promising something they cannot achieve, and also something they both know would have a negative economic impact if they did manage to achieve it.

Voters are not stupid; they will see through this. The vast majority of people who oppose immigration and for whom immigration is a major issue will vote UKIP. No transparent, empty promise from Labour or the Tories will change their minds.

If Cameron and Miliband want to earn people’s votes, they should tell them the truth, not what they want to hear. We cannot limit immigration from Europe while we remain a member of the EU. Immigration is good for the economy. Voters have been lied to for too long on immigration. Only when Labour and the Tories start to tell them the truth, will they start to win their votes back.