Bob Crow is impressed with the SSP

Bob Crow, general secretary of the Rail Maritime and Transport Union (RMT), said the Scottish Socialist Party (SSP) shared common ground with his union.

He told BBC Radio Scotland that union members are getting "fed up" with New Labour and have already cut the amount of money it gives them.

The RMT boss sounded the warning as the union prepared for its annual conference in Glasgow.

Our position at the moment is that we will remain affiliated to the Labour Party until somebody else comes along. That could well be the SSP. Bob Crow

Mr Crow said his union was not going to give money to "people who would put the boot into us" and said the union movement would be "kicking up hell" if the Tories had introduced some of Labour's current policies.

He said of the SSP: "They want to renationalise the railway network, new Labour doesn't - so why should our members carry on supporting them?"

Mr Crow said his union's Scottish members were increasingly viewing the SSP as a better alternative to Labour.

"Certainly I believe we will be looking to support the SSP," he said.

"Our position at the moment is that we will remain affiliated to the Labour Party until somebody else comes along.

"That could well be the SSP. If they are going to campaign for stopping Caledonian MacBrayne being sold off, if they're going to fight for the renationalisation of the railway, I think our members in Scotland will look to support the SSP."

The SSP have six MSPs in the Scottish Parliament and can trace their origins to the campaign against the poll tax.

They favour higher taxes, renationalisation and big increases in public spending to end poverty.