A national strike Wednesday in Britain is expected to disrupt schools, hospitals, airports, shipping ports and government offices nationwide.

Workers are expected to protest government plans to reduce a $185 billion budget deficit by reducing pension benefits, increase pension payments and forcing longer work hours.

The Trades Union Congress, an umbrella organization of British labor unions, has called on more than 2 million workers to join the strike against the government plan. The walkout is expected to be the biggest in three decades.

The government says it will not be swayed by the strike because the current pension system is no longer affordable. Officials have warned unions that their action will cost the economy close to $800 million.

The operator of Heathrow Airport warned that customs and immigration services could be reduced by at least 50 percent. On an average day, Heathrow airport handles more than 180,000 passengers.

London's second largest airport, Gatwick, has warned passengers to expect delays and gridlock.