The link between Labour and the RMT was formed in 1899

The Rail, Maritime and Transport union faces being thrown out of Labour after it voted to continue allowing branches to affiliate with other parties.

Labour had previously told the union that it would be disaffiliated at noon on Saturday unless it changed its mind.

Delegates at a special conference in Glasgow rejected Labour's threat.

The best way to treat a bully is to stand up to them and not run away Bob Crow RMT general secretary

Labour chairman Ian McCartney said he was "deeply saddened" by the decision which he warned would leave the RMT out in the cold.

The dispute began last year when the RMT, unhappy with some of Labour's policies, allowed five of its branches in Scotland to affiliate to the Scottish Socialist Party (SSP).

Two more branches and the Scottish Regional Council now also want to switch affiliation.

At Friday's conference, RMT delegates voted by 42-8 to uphold the decision.

RMT general secretary Bob Crow accused Labour of "arrogance" and said the party was trying to bully the RMT into changing its policy.

'Clear message'

He complained that the union had not been told which rule it had broken and was not being given a chance to appeal or even state its case.

"Some people in the Labour Party have contributed nothing to working people yet they have the cheek to tell us to write a begging letter by 12 noon tomorrow.

"We should send a clear message that we are not going to be dictated to by the Labour Party.

"The best way to treat a bully is to stand up to them and not run away."

RMT general secretary Bob Crow accused Labour of "arrogance"

Mr Crow revealed that fewer than 500 of the RMT's 70,000 members were in the Labour Party.

The union has reduced its affiliation to Labour to just �12,500 a year but it has a seat on the party's executive.

Tommy Sheridan, whose SSP will benefit from the move, said he believed that many other unions would now consider their links with Labour.

He said: "The Labour Party used to represent millions, now it represents millionaires."

Mr McCartney said: "I am deeply saddened by the news that Bob Crow and his controlling group has actively chosen to leave the Labour Party.

Splinter group

"As a former member of the union I am sad to see that Bob Crow has led the RMT out into the cold.

"He has taken the RMT out of Labour's annual conference and Labour's National Policy Forum which will shape Labour's next manifesto and he has taken his union outside the NEC, which gives the RMT a seat at the table with the Prime Minister and Deputy Prime Minister.

"And for what? To have the privilege of sitting around the table with a small Trotskyite splinter group."

In a letter sent to the RMT in December, Labour said the union's actions breached clause 11.4 in chapter one of the party's rule book.