There have already been two Tube strikes this month

The Rail, Maritime and Transport union has said it is to ballot 1,500 members, claiming industrial relations with London Underground (LU) have collapsed.

Aslef is balloting its members on issues ranging from health and safety to allegations of harassment.

An LU spokesman said the company was committed to resolving disputes through consultation and negotiation.

RMT leader Bob Crow said they were "ready to talk", but accused LU of trying to force through new policies.

'Out of patience'

"Once again Tube management have jumped the gun and are trying to impose policies without agreement," he said.

"Maybe they think there will be a management shake-up following the appointment of the new commissioner but they are running wild, trying to out-militant each other and our members have run out of patience."

Both ballots will close on 9 February and the RMT says any action would be co-ordinated.

We are committed to a culture of fairness and trust between management, employees and trade unions London Underground

The LU spokesman said they wanted to resolve issue through discussions.

He said: "Given these negotiations have not even begun, we are surprised Aslef and the RMT appear to be ignoring the agreed machinery of negotiation and have moved to ballot.

"We are committed to a culture of fairness and trust between management, employees and trade unions, to honouring agreements and to building constructive employee relations."

The action is not linked to two recent strikes by station staff over new rotas. RMT members are being urged to accept a deal to resolve that dispute.

Former transport commissioner Bob Kiley stepped down this month and has been replaced by Peter Hendy, who had been responsible for London's buses.