Downing Street has distanced itself from calls by the transport minister, Chris Grayling, and Tory backbenchers for new anti-strike laws as unions plan a wave of industrial action this week and over the festive period.

A spokesman for No 10 said the laws governing industrial action cannot be changed to halt current disputes, which are a matter for unions and employers.

Grayling angered many union leaders last week by saying he would “not rule anything out” when asked if he might change the law to prevent future rail strikes.

Former cabinet ministers Lord Heseltine and Lord Tebbit are among the Tory figures who have called on Theresa May to take a tough line on trade unions.

A Downing Street source said there were no plans to change current union laws, which remain under review. “Any changes to union laws would not be able to solve the current disputes. They will be solved by mediation and we would urge the unions to get round the table.

“In this parliament, we have already passed legislation to provide people with better protection from undemocratic industrial action. Of course, we will keep under review how these measures are working in practice,” the source said.

Industrial action by conductors in the RMT union on the Southern rail franchise – coupled with a continuing ban on overtime by drivers in the Aslef union – is expected to bring a second week of havoc to 300,000 passengers between London and the south coast on Monday and Tuesday.

The RMT strikes are part of a long-running dispute over the role of conductors, with further walk-outs planned for next month. Aslef has joined the RMT dispute, striking for three days last week and entirely shutting down the Southern network.

British Airways and Virgin Atlantic are also facing walkouts over Christmas. Talks aimed at averting strikes by British Airways cabin crew over Christmas will be held at Acas on Monday. Members of Unite are due to walk out on Christmas Day and Boxing Day in a dispute over pay.

There will be talks on Tuesday between the airport services company Swissport and Unite, aimed at averting a 48-hour strike due to start on Friday by 1,500 baggage handlers and other airport staff in a dispute over pay.



The Post Office is facing possible shutdowns of branches as members of the Communication Workers Union (CWU) strike in a pay dispute.



Last week, Grayling told the BBC that he would look at all options to stop rail unions from striking, and while he wasn’t “ruling anything in” he wasn’t “ruling anything out” either.



Heseltine told the Sunday Telegraph: “You cannot have small groups of people holding society to ransom, regardless of personal inconvenience or cost.”

It was reported that about 20 MPs had called on Grayling to take action against strikes.

MPs in seats across Southern’s network have faced angry demands for action from their constituencies, although the Department for Transport has declined to get involved in the long-running dispute between Southern’s operator, Govia Thameslink Railways (GTR), and Aslef and the RMT.

Labour MPs, however, appear to be split over how to approach the dispute. The shadow home secretary, Diane Abbott, has defended unions planning to strike. “Of course these strikes are going to be very disastrous if they all go ahead for the public over Christmas, but people do have a legal right to strike,” Abbott told the Sky News presenter Dermot Murnaghan on Sunday. She added: “It’s not my role to second-guess the decisions of trade union leadership.”

But Meg Hillier, the Labour MP who chairs the public accounts committee, warned on the same programme that unions could be “shooting themselves in the foot” by opting for industrial action over the festive season. “There needs to be a wake-up call about the impact on hard-working people trying to get to work or go on holiday,” she said.

The RMT’s general secretary, Mick Cash, was forced to deny that the union was part of a “Trot conspiracy” after the Sunday Times published a video showing the RMT union president, Sean Hoyle, at a rally saying trade unions were working together to “bring down this bloody working-class-hating Tory government”.



Cash said: “We are a serious trade union dealing with serious issues around safety on the railways. That is our absolute priority. RMT is not party to any Trot conspiracy to bring down government.”

RMT has spent months locked in a bitter dispute with GTR over the company’s plans to introduce driver-only trains, which would allow some services to run without a second staff member on board. The company says this would reduce delays and cancellations when a second staff member is not available. The union says it would pose a safety risk.

On Friday Aslef’s general secretary, Mick Whelan, wrote to members that talks at mediation service Acas had been unsuccessful, and “at no time during the course of discussions did the company make any kind of formal offer” to end the dispute. A GTR spokeswoman said no further talks were planned but “our door remains open”.

The Royal Mail has said it does not anticipate trouble for postal services in the run-up to Christmas despite a planned strike on Monday, Tuesday and Saturday by Post Office staff belonging to the CWU.

A spokeswoman for the Post Office said the strike would only affect the 300 branches it directly manages, as the majority of the country’s 11,000 branches are managed through franchise arrangements.