Thousands of British teachers and civil servants Thursday are participating in a 24-hour strike, protesting proposed changes to pension plans calling for higher contributions and longer working lives.

Many schools across Britain were closed and travellers delayed due to the estimated 750,000 workers participating in the labor walkout.

The UK Border Agency encouraged travellers to have passports and travel documents ready for inspection in an effort to alleviate delays.

Prime Minister David Cameron made a final plea Tuesday to persuade the workers to abandon the strike.