A rally will be staged on Friday afternoon

Q: Why did PCS members vote to strike?

It stems from government proposals to axe more than 100,000 jobs.

The union says the action also comes at a time when civil servants are facing changes to their terms and conditions, sick absence arrangements and the prospect of working longer to receive their pension as the pension age could rise from 60 to 65.

Q: How many people voted to strike?

Of the 265,000 union members, around 42% took part. Of those, 64.5% (around 73,000 people) voted in favour of strike action.

Q: How many people are involved in the strike?

All 265,000 members were asked to come out on strike. That includes people working in job centres, benefit agencies and pensions offices as well as customs officials and driving test examiners.

The PCS Union estimates up to 200,000 civil servants across the UK were on strike on Friday. Those on strike range from staff at museums, the Royal Parks, Inland Revenue, customs and immigration officials, and driving instructors.

The strike may prove to be the biggest industrial action in the civil service since 1993. It is affecting 160 government departments.

Q: How will the public be affected by the action?

The strike has also affected the DVLA, Inland Revenue offices, passport and pension services and some museums and libraries.

Q: What is the government's reasoning behind the job cuts?

Chancellor Gordon Brown announced his decision to make the cuts - which would reduce the civil service by one fifth - in July as part of a cost-saving exercise which aims to automate many back-office jobs.

The Cabinet Office says the cuts will allow it to take on more police, teachers, doctors and nurses.