The Government warned the main rail workers union today that the future of industrial relations was in its hands after a series of strikes were announced on London Underground in an escalating row over the sacking of two Tube drivers.
Members of the Rail Maritime and Transport union will take six days of action over two weeks later this month and in June, threatening travel chaos for millions of passengers.
Transport Secretary Philip Hammond said the strikes would do "absolutely no good" for London, adding: "The unions need to understand that the future of industrial relations in this country is in their hands. There is no appetite in Government for a confrontation but if the unions behave irresponsibly they are simply strengthening the arguments of those who want changes to our industrial relations laws and those who are demanding a higher voting threshold."
There have been calls for the law to be changed so that a majority of those eligible to vote, rather than those who take part in a ballot, will have to back industrial action before strikes can be held.
The RMT said around 1,500 Tube drivers will walk out for between nine and 24 hours from Monday May 16 to Friday May 20 and again from Monday June 13 to Friday June 17.
The move follows a 2-1 vote in favour of industrial action by RMT members in protest at the dismissal of Northern Line driver Eamon Lynch and Arwyn Thomas, a Bakerloo Line driver. Both men have taken a case of unfair dismissal to an employment tribunal.
Both men were given an "interim relief" by an employment tribunal, although their full cases have yet to be heard.
The RMT said interim relief was only granted by a tribunal where there was the clearest possible evidence that an employee had been dismissed on the grounds of their trade union activities.
Mr Lynch is the RMT's Bakerloo Line drivers' health and safety representative.
The union claimed that Mr Thomas, a long-standing RMT activist, was sacked on "trumped-up" disciplinary charges following allegations made against him after an incident during last year's strike.
LU strenuously denies the union's claims.
RMT general secretary Bob Crow said: "It is the abject failure of LU to recognise that their policy of victimisation of union activists has been well and truly rumbled both in the employment tribunal and in their own depots, and it is that harassment and bullying that has left us with no choice but to name these dates for strike action.
"The solution is simple - LU should accept that they have been found out, get these drivers back to work doing the job that they are being paid to do and bring an end to the constant harassment of union activists whose only crime is fighting cuts to jobs and safety."
LU managing director Mike Brown said: "Just 29% of the 1,300 drivers balloted voted for this strike.
"We know that the vast majority of drivers work safely with the utmost respect for passengers and their fellow workers at all times.
"The cases concerned are still going through the employment tribunal process and Transport for London will of course respond to whatever conclusions are reached in this process.
"The RMT leadership seems determined to disrupt London and its economy over several days. As ever, London Underground and TfL will work to keep London moving if the strikes go ahead."
London Mayor Boris Johnson, said: "Even by the grim standards of the RMT leadership, the series of strikes they are now seeking to inflict on their members and fellow Londoners are unbelievable.
"Most train drivers did not vote for this action, no-one in London will support them, and to pre-empt the results of an industrial tribunal by resorting to industrial confrontation is immoral, irresponsible and idiotic."
Labour's London mayoral candidate, Ken Livingstone, said: "Tube users are fed up to the back teeth of worsening industrial relations on the Underground that leave them inconvenienced time after time."
The strikes will be held between 21:01 on Monday May 16 and 11:59 on Tuesday May 17, between 1200 on Wednesday May 18 and 1159 on Thursday May 19, and between 1200 and 2100 on Friday May 20.
Further walkouts will be held between 2101 on Monday June 13 and 1159 on Tuesday June 14, between 1200 on Wednesday June 15 and 1159 on Thursday June 16, and between 1200 and 2100 on Friday June 17.