Britain faces its biggest strike in 30 years next week, a one-day walkout over public-sector pensions, with the prime minister urging parents to take their children to work as schools close and diplomats being flown home to staff border controls.

The action will test whether once-mighty trades unions, hamstrung by strict labour laws and a shrinking membership, can still have an influence on policy.

After months of heated negotiations which have gone nowhere, about two million public sector workers are to strike on November 30 over austerity measures by the Conservative-led coalition government that will make them pay more for their pensions and work for longer before they can retire.

Ministers are so concerned about the impact they are calling some embassy staff home to stand in for striking immigration officers. The strike is expected to close thousands of schools, cause chaos to ports and airports, and disrupt services as diverse as refuse and tax collection.

Enough is enough, Mark McSheehy, 43, a Community Nurse Assistant from Exeter told Reuters.

I'm a single parent with a 10-year-old daughter to support, with bills rising it's a struggle already and now they want more, he said.

McSheehy, who earns less than the national average of 26 thousand pounds a year, has worked for the health service for 20 years and has never been on strike before. He says many of his colleagues feel the same way.

We feel robbed. We've already had a two-year pay freeze and now this.

Nicola Goodwin, a custody detention officer for a police force in Wales, said she had no choice but to join the action. Under these proposals, I'll be paying around an extra 68 pounds per month, that's the equivalent of a full tank of petrol. It makes me angry, these proposals are totally unfair.

A report that pay for directors of Britain's top 100 companies rose 49 percent last year has added to the sense of outrage amongst the low-paid, many of whom work in the public sector.

The government says the strike could lead to job losses and cost more than half a billion pounds in lost output, a figure the Trades Union Congress (TUC), an umbrella group coordinating the walkout by 30 unions, dismissed as fantasy economics.

Unions, many of whom have saved up a war chest of funds to pay striking workers, say it is the first in a wave of national one-day strikes running into next year, challenging a government that is trying to juggle cutting a budget deficit that peaked at a record 11 percent of economic output with fostering growth.

If there is a big turnout next week and the government digs in there will definitely be more strikes, I can't see them (unions) stopping, said Roger Seifert, professor of industrial relations at Wolverhampton University.

The mood is hardening, the government isn't helping and people look across the English Channel (to Europe) and think 'we need to do something'; the mood is very grim and pretty determined, said Seifert.

So far, Britain has avoided the large-scale strikes and protests seen in other European countries including Greece, France, Portugal, Denmark, the Czech Republic and Serbia over austerity plans and cuts to pensions.

1970S? RUBBISH

Despite the big numbers likely to be involved, commentators say the strike does not herald a return to the late 1970s and the 1980s when rubbish piled up in the streets and labour disputes came to define an era when Conservative Prime Minister Margaret Thatcher took on the unions and won.

Ian Brinkley, director of the Work Foundation consultancy, says historical comparisons in the media with the Winter of Discontent action in 1979 that brought 1.5 million workers out are exaggerated.

The Winter of Discontent that brought down the Labour government and the huge set piece conflicts between the miners and Mrs Thatcher and between the print workers and the (Rupert) Murdoch press (in the 1980s) were much more serious disputes, said Brinkley, who worked for the TUC for more than 20 years.

All of those were a watershed both in terms of industrial relations but also economic change ... This is not a formidable industrial steamroller, he said, referring to the coalition of unions involved.

He noted the strike involves public-sector workers and not those in the private sector too as happened in the late 1970s.

Analysts also point out unions no longer have the power they once had, partly because of declining membership but also the strict labour laws introduced by Thatcher's government.

Membership fell through the 1980s from 56 percent of the British workforce at the start of the decade when Thatcher took power to little over a quarter in the last few years. Days lost to strikes have also plunged in the last 40 years.

Britain has some of the most restrictive strike laws in the Western world and analysts say such rules could put unions off from taking more action despite many threatening to call more nationwide walkouts well into next year if the government fails to negotiate over pensions.

The web of complex rules, which can easily trip up unions, include balloting members by post, notifying employers in detail about those to be balloted and giving advanced notice of industrial action.

WHAT NEXT?

Experts are split on what the strike will achieve and whether unions have the resolve and capability to continue with a wave of stoppages.

Public opinion will also play a role in what happens next. A YouGov poll for the Sunday Times newspaper last week found that 52 percent of people questioned were against pension strikes with 35 percent in favour.

The key question is what goes on beyond November 30 because I think what will happen is workers will tire fairly quickly, said Professor Jonathan Tonge, head of politics at Liverpool University.

There is very little that one or two one-day strikes can really achieve. For instance, if university lecturers walk out, frankly who cares, who cares that students aren't taught for a day. It's a mindless tactic from days gone by, he said.

The Work Foundation's Brinkley said: This isn't like the days of the famous Triple Alliance, between railworkers, coalworkers and steelworkers (in the 1970s), which could bring the economy to a halt. They just don't have that power anymore.

(Reporting by Stefano Ambrogi; Editing by Janet Lawrence)