Network Rail workers are to stage two strikes next month after a new pay offer was rejected.

Members of the Rail, Maritime and Transport (RMT) union will walk out for 24 hours from 5pm on June 4 and for 48 hours from the same time on June 9.

The workers, including signallers and maintenance staff, will also ban overtime from June 6 until June 12.

A planned strike over the bank holiday was suspended after Network Rail tabled a fresh pay offer.

But a meeting of RMT reps rejected the improved deal, leading to fresh strikes being announced.

The industrial action is expected to cause widespread disruption to rail travel, sparking travel chaos across the south-east London and Kent.

A spokesman for Southeastern said: "Special arrangements are being put in place to ensure customers who already have tickets are not disadvantaged and can travel on an alternative day or obtain a refund if they choose not to travel.

"We are working closely with Network Rail on contingency arrangements and further information will be made available shortly."

RMT members voted by 80 per cent for strikes and 92 per cent for other forms of industrial action, in a 60 per cent turnout - all well above new thresholds being planned for union ballots by the Government.

Transport Secretary Patrick McLoughlin said: "Millions of hardworking people will be disrupted by this unnecessary and unreasonable strike action. I condemn it wholeheartedly and urge the union to reconsider.

"Over the past four years Network Rail staff have enjoyed pay rises eight times higher than other public sector workers. By any measure RMT members already get a fair deal.

"It is very disappointing that RMT has now rejected a deal delivered through Acas talks that the union's leadership agreed was a reasonable offer.

"The Government will do everything it can to help keep people and goods moving during the strike."