LONDON - Up to half a million British teachers, civil servants, train drivers and university lecturers will strike on Wednesday in the largest coordinated action in a generation which the government says will cause widespread disruption.

The mass walkouts will see schools close, the military on standby to help at Britain's borders, and no rail services running across much of the country.

Union leaders estimate up to 500,000 people will take part, the highest number for at least a decade, and there will be rallies against a planned new law to curb strikes in some sectors, a proposal they argue will poison relations further.

"After years of brutal pay cuts, nurses, teachers and millions of other public servants have seen their living standards decimated – and are set to face more pay misery," said Paul Nowak, General Secretary of the Trades Union Congress (TUC), the union umbrella group.

"Instead of scheming up new ways to attack the right to strike, ministers should get pay rising across the economy – starting with a decent pay rise for workers across the public sector."

The government says "mitigations" will be in place but the strikes would have a significant impact.

"We are up front that this will disrupt people's lives, and that is why we think that negotiations rather than picket lines are the right approach," Prime Minister Rishi Sunak's spokesperson told reporters.

With inflation running at more than 10% - the highest level for four decades - Britain has seen a wave of strikes from health and transport workers to Amazon warehouse employees and Royal Mail postal staff.

They are demanding above-inflation pay rises to cover rocketing food and energy bills that they say has left them stressed, feeling under-valued and struggling to make ends meet.

On Wednesday, about 300,000 teachers will take action, along with 100,000 civil servants from more than 120 government departments, and tens of thousands of university lecturers and rail workers.

Next week, nurses, ambulance staff, paramedics, emergency call handlers and other healthcare workers are set to stage more walkouts, while firefighters this week also backed a nationwide strike.

'MOST DAYS LOST FOR 30 YEARS'

Between June and November, more days were lost to industrial action than in any six months for over 30 years, according to official data.

An Ipsos poll released on Wednesday suggested the public was divided on the multiple strike action, with 40% supporting the action and 38% opposed.

Sunak's government has so far taken a hard line with public sector strikes, saying that to give in to demands for large wage increases would only fuel inflation.

But with his governing Conservatives trailing the opposition Labour Party by some 25 percentage points in polls, the industrial action is adding to Sunak's political woes, and surveys indicate the public think the government have handled the strikes badly.

So far the economy has not taken a major hit from the industrial action with the cost of the strikes in the eight months to January estimated by consultancy firm the Centre for Economics and Business Research (CEBR) at about 1.7 billion pounds ($2.09 billion), or about 0.1% of expected GDP.

It put the estimated impact of the teachers' strikes at about 20 million pounds a day.

However, with confidence weak among the public and employers and the economy in a downturn, the strikes were adding to a sense of gloom in Britain's economy.

"Unresolved industrial disputes are having an adverse impact on growth at a time when recession is already expected imminently," CEBR economist Karl Thompson said.

($1 = 0.8130 pound)

(Reporting by Michael Holden, Alistair Smout and William Schomberg; editing by Jonathan Oatis)