British Prime Minister Gordon Brown, waded into the acrimonious dispute between British Airways PLC and its cabin crew on Monday, calling a planned strike by workers “deplorable” and urging union leaders to cancel the walkout.

Brown’s rare direct intervention in an industrial matter comes ahead of a looming general election, which political analysts expect to be a close run affair with the ruling Labour Party currently lagging in the polls behind the main opposition Conservative Party.

The walkouts scheduled by the Unite union for a total of seven days in the run—up to the busy Easter holidays are expected to affect hundreds of thousands of travellers.

There are also fears of wider industrial unrest after thousands of rail workers voted in favour of strike action that their union has said will likely target the Easter long weekend.

“It is the wrong time, it is unjustified, it is deplorable, we shouldn’t have a strike,” Mr. Brown told BBC radio of the BA walkout. “It is not in the company’s interest, it is not in the workers’ interest and it is certainly not in the national interest.”

Mr. Brown’s public hardline stance against Unite, one of the Labour Party’s major donors, comes after he spoke with the union’s leaders over the weekend.

The union is enraged at the intervention, calling Brown’s Transport Minister Andrew Adonis, “badly informed” after he too spoke out against the walkout.

The planned action is the latest move in a long—running dispute between Unite’s 12,000 cabin crew members and BA management over a pay freeze and changes to working conditions that also led to a narrowly averted strike over the Christmas and New Year break. The courts ordered that walkout be cancelled because of technical irregularities in Unite’s ballot of its members.

Negotiations since then to try to find a resolution have failed amid accusations from Unite of intimidation and charges from BA that the union is trying to bring the airline to its knees.

The carrier has been particularly hard hit by the global economic recession because of its heavy running costs and reliance on increasingly unpopular first— and business—class fares.

It argues that the disputed changes - including a pay freeze in 2010, a switch to part—time work for 3,000 staff and a reduction in cabin crew sizes from 15 to 14 on long—haul flights from Heathrow airport - are critical for its survival.

Unite argues it was not properly consulted on the changes and that the airline has ignored valid alternatives.

Unite had planned to put the latest offer from BA to workers before the announced strike dates - three days from March 20 and four days from March 27 - and pledged to call off the walkouts if they approved.

However, union leaders added they would not recommend the offer and BA retaliated by pulling it off the table.

BA Chief Executive Willie Walsh, has said he remains available for talks 24 hours a day, but stressed that he planned to focus on looking after the airline’s customers.

BA has been training around 1,000 workers who volunteered from other departments at the airline to stand in for cabin crew in the event of a walkout. Unite has attacked that decision, saying it will put BA’s passengers’ at risk in emergency situations.

The airline is also trying to obtain seats on flights operated by rival airlines to pass on to its own customers.

It has said it plans to operate all flights from London City airport, including long—haul services to New York. From Gatwick, it plans to operate all long—haul services and about 50 percent of short—haul. From Heathrow, it plans to operate a “substantial part” of both long—haul and short—haul schedules.

Unite stuck by a pledge not to hold a strike over the busy Easter period, after the planned Christmas walkout resulted in a public backlash against workers. But Unite assistant general secretary Len McCluskey, said further action would take place after April 14 if the dispute is not resolved.

The RMT rail union, which represents some 10,000 rail workers around the country, revealed last week that maintenance workers had voted in favour of a walkout. It has not yet announced strike dates, but RMT leader Bob Crow, warned passengers not to make travel arrangements over Easter.