Rail networks in the United Kingdom faced major disruption again on Wednesday as 40,000 staff members walked out in a row over pay and working conditions, the latest in a wave of industrial unrest as wages fail to keep pace with soaring inflation.

The 24-hour strike by cleaners, signalers, maintenance workers and station staff comes a month after the country’s most disruptive rail walkout in three decades brought trains to a halt across the U.K at the start of the summer holiday season.

The latest action by the members of the RMT and TSSA unions forced around half of Britain’s rail network to close, with train companies operating a much-reduced timetable and some parts of the country having no rail service at all.

Network Rail urged passengers, including commuters, families heading off on summer holidays, and sports fans on their way to the Commonwealth Games in Birmingham which begins on Thursday, to only travel if necessary.

Changing working practices during the coronavirus pandemic meant many office workers were able to opt to work from home.

Strike action last month brought Britain’s rail network close to a standstill for three days and just last week some key lines running the length of the country were forced to close when record temperatures damaged the track.

There were almost 1 billion train journeys in the U.K. in the year to March, compared to 1.7 billion in the 12 months before the pandemic, and rail companies are looking to cut costs and staffing.

"Our members are more determined than ever to secure a decent pay rise, job security and good working conditions," RMT general secretary Mick Lynch said in a statement.

"Network Rail have not made any improvement on their previous pay offer and the train companies have not offered us anything new."

Lynch said the union "will continue to negotiate in good faith, but we will not be bullied or cajoled by anyone."

The RMT union said it had received an offer of a 4% rise, followed by a possible 4% the following year dependent on staff accepting changes to their contracts.

Transport Secretary Grant Shapps accused union leaders of "trying to cause as much disruption as possible to the day-to-day lives of millions of hardworking people around the country."

He said the strike had been "cynically timed" to disrupt a semi-final of the European women’s soccer tournament on Wednesday in Milton Keynes, north of London, and the opening of the Commonwealth Games.

Inflation in Britain is running at a 40-year high of 9.4% and is expected to reach double digits later this year, driven by surging fuel and food prices.

Soaring inflation and more than 10 years of stagnant real wages have triggered Britain’s worst cost-of-living crisis since records began in the 1950s, exacerbating labor tensions across sectors including postal services, health, schools, airports and the judiciary.

It has also become a point of contention in the race to replace Boris Johnson as prime minister, with the final two candidates, Liz Truss and Rishi Sunak, vowing to crack down on strike action.

The government last week changed the law to make it easier for businesses to use temporary staff to minimize the impact of strike action.

Ferry services to Cowes in the Isle of Wight will also be disrupted on Wednesday due to strike action, and a new train strike is expected on Saturday.