Updated

Britain's Home Office is seeking an injunction to halt a strike on the eve of the Olympics by immigration staff at U.K. airports.

Members of the Public and Commercial Services Union, which represents staff at British airports, voted last week for a 24-hour walkout over pay and job losses. The strike is set for Thursday — the day before the start of London's Olympic Games.

The Home Office said Tuesday the government believes there was a procedural error in the strike ballot and it is seeking a High Court injunction to prevent the strike.

It urged the union to call off the strike and for its members not to walk out when "the eyes of the world" will be on the U.K.

The union said it will "robustly defend" any legal challenge to the planned strike.

"We would hope ministers would rather sit down and talk to us, instead of going to the courts," the union said in a statement.

During previous border guard strikes in November and May, the government drafted in managers and civil servants — including Prime Minister David Cameron's press secretary — to help staff immigration desks and minimize the disruption to incoming travelers.

Britain's government is eager to avoid any disruptions at U.K. airports as visitors descend for the July 27-Aug. 12 games.

Prior to a massive push to quickly process Olympic athletes and visitors, Heathrow Airport, Europe's busiest, had been beset for months by long lines at passport control, which the union has blamed on government spending cuts.