Transport Secretary Grant Shapps told the Sunday Telegraph a potential change in legislation could allow companies to hire temporary workers to cover some roles and prevent disruption.

Any intervention would not affect the rail strikes across Britain this month.

But Mr Shapps said changes could be brought in quickly to minimise future action in rail or other sectors.

A war of words between rail unions and ministers has been escalating since the RMT union announced three days of strikes, after talks about pay, terms and conditions, and redundancies fell through.

Mr Shapps said should the action continue then “further measures certainly would come in during this particular dispute, if it can’t be resolved”.

“We will be looking at the full suite of modernisation that’s required,” he told the Telegraph. “The country must not continue to be held to ransom.”

The transport secretary said any change could involve secondary legislation, which can be signed off by ministers “very fast”.

Meanwhile, writing in the Sun on Sunday, Mr Shapps warned rail workers who plan to strike this month that they will not be able to work overtime on subsequent days to top up pay they will lose as a result of taking part in the action. It is is understood this is because rail companies may decide to run restricted timetables after the strike days.Transport Secretary Grant Shapps said the country “must not continue to be held to ransom”

Mr Shapps’ comments come less than a month after rail unions reacted with fury to a government threat to make strike action illegal unless a minimum number of train staff remained working during a walkout.

In response, RMT general secretary Mick Lynch said “any attempt” by Mr Shapps to “make effective strike action illegal on the railways will be met with the fiercest resistance from RMT and the wider trade union movement”.

More than 40,000 RMT members working for Network Rail and 13 train operating companies across Britain will strike on 21, 23 and 25 June.

In a separate dispute over pensions and job losses, the RMT’s London Underground members will also strike on 21 June.

The RMT is calling it the biggest dispute for over three decades and put the industrial action down to the “inability of the rail employers to come to a negotiated settlement”.

Train and tram drivers, part of the Aslef union, are also set to strike in three locations this month.