Chancellor Alistair Darling will have to cross picket lines today (Wednesday) as civil servants stage their first ever Budget Day strike in a bitter row over redundancy pay.

Members of the Public and Commercial Services (PCS) union will stage a 24-hour national walkout, following a two-day stoppage earlier this month, which is set to disrupt courts, jobcentres, benefit offices, driving tests, prisons and ports.

The stoppage will also see civilian staff and 999 operators working for the Metropolitan Police walking out, as well as security staff working in the Houses of Parliament.

Strikers will mount picket lines outside the Treasury, Downing Street and Parliament, which the Chancellor will have to cross to deliver his Budget in the Commons at lunchtime today.

A number of Labour MPs are expected to remain in their constituencies today rather than cross PCS picket lines.

A union battle bus will tour picket lines in London and a campaign boat will cruise up and down the River Thames outside the Houses of Parliament.

Demonstrations will also be held across the UK, including an “alternative Budget” presented in Edinburgh and rally on the steps of the Welsh Assembly in Cardiff.

The last two-day stoppage saw the cancellation of business in the Welsh Assembly and the Scottish Parliament when assembly members and MSPs refused to cross picket lines.

PCS general secretary Mark Serwotka said: “It is no coincidence that PCS members are striking on Budget Day to defend jobs and services. As the Government seeks to make it easier and cheaper for whoever wins the election to cut civil and public servants, we can expect a drive to slash jobs which will ultimately lead to poorer services.

“Loyal civil servants have already seen the damage that 100,000 job cuts has wrought and will not stand by and allow the jobs and services they are proud to deliver slashed.

“In the Budget, the Government has an opportunity to stamp out tax avoidance and evasion by companies and wealthy individuals. Alongside dealing with uncollected taxes, this would provide over £100 billion towards cutting the deficit.

“The Government needs to start valuing its own workforce by standing up for public services and reaching an agreement on redundancy pay that protects people’s entitlements.”

The union is also taking legal action against the Government over cuts to the level of redundancy paid to civil servants losing their jobs. The case is due to be heard on April 22 and 23.