Police chiefs are refusing to yield to trade union demands to allow protesters to march past Birmingham’s International Convention Centre at the start of the Conservative Party conference this weekend.

Representatives from six unions are hoping for a last minute change of heart, but a police spokesman said the marchers would not be permitted to pass along Broad Street directly in front of the ICC because the area will be a secure zone.

The police have instead offered an alternative route allowing the Right to Work Campaign to pass “within sight” of the ICC on Sunday.

The protesters claim that this will be the first time demonstrators have been banned from gathering outside a party conference.

Chris Bambery, secretary of the Right to Work Campaign, said: “Even immediately after 9/11, and in the aftermath of the Iraq invasion, protesters were allowed to march past the governing party’s conference.

“Last year Right to Work marched past the front entrance of the Labour conference in Brighton.

“David Cameron will be meeting in something more resembling central Baghdad’s Green Zone. I would ask what has he got to be scared of?

“There is still time for the police to rethink their decision, and I urge them to do so. But whatever happens we will march in our thousands and ensure Tory delegates can hear us behind their security barriers.”

The march starts from Lionel Street at 12 noon.