(Bloomberg) -- Some of London’s biggest railway stations are shut on Thursday while airports such as Gatwick are also deprived of any train services, as workers strike again and union bosses warn of more industrial action to come.

Commuter services into the capital run by Thameslink, Southern and Southeastern came to a complete halt. Train drivers represented by the Aslef union are walking out following a long dispute over pay.

“The longer this goes on, the likelihood of escalations goes up,” Mick Whelan, Aslef’s general secretary, said from a picket line in London. “I’m due to retire in three years — I’d like it resolved before then.”

Whelan said he’d be meeting ministers on Monday and urged them to play a bigger part in negotiations. The government has said it’s ultimately down to train companies and unions to find a compromise.

Britain is mired in industrial action with workers ranging from train drivers to nurses and border-control officials protesting against below-inflation pay offers. In retaliation, the Conservative government is planning new legislation to force workers in crucial sectors to maintain service levels while on strike.

The latest walkout has been labeled “Tragic Thursday” by rail bosses due to its effect on services. It comes in the middle of four days of separate strikes held by the RMT, another labor group. While the RMT is not technically on strike Thursday, services have been crippled by Aslef’s industrial action.

The effect is more severe than on the days affected by the RMT’s strikes. London Bridge, Victoria and City Thameslink have no services at all. There are also none on the West Coast main line which connects London to Birmingham, Manchester and Glasgow.

Some rail operators are running a heavily reduced service, such as Great Western Rail, which is providing one hourly train into Paddington. That is compared with four hourly trains on previous RMT strike days.

Travelers to and from Gatwick airport will have to make their way by road. However, most of the hub’s coach services run by National Express Group Plc have already sold out. Neither are there any trains to Luton airport, served by low-cost giant EasyJet Plc.

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Bus services in west and south London are disrupted as a strike by Abellio workers rolls into its second day.

Aslef recently re-balloted members and now has a mandate to take further strike action up until June. Talks between union bosses, ministers and train company executives are expected to resume at the start of next week.

(Updates with quotations from Aslef’s general secretary in third paragraph.)

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