Rank-and file police officers are to stage a protest over proposed changes to their pay and conditions.

The Police Federation, which would not confirm what its plans will involve, said it is planning to hold an event in central London on May 10.

It comes as the federation's 135,000 members across England and Wales are being balloted on whether they want the right to strike.

Along with the armed forces and prison officers, the police are banned in law from taking industrial action.

Many officers are angry with the Government in the wake of 20% budget cuts and proposals for the most wide-ranging reform of police pay and conditions in more than 30 years.

The national federation said the event would "highlight officer concerns about cuts to policing".

It has previously said the event would show "the unprecedented attack on policing by this Government and the consequences that these cuts will have for public safety".

Its Greater Manchester branch added that it would be "arranging for officers to go to London and show the world their anger at these impractical and unworkable proposals".

Tom Winsor's 18-month review of police pay and conditions signalled the end of a job for life as he called for the ban on chief constables making officers redundant to be lifted in the face of budget cuts.

The current pay system, which was based on a 1920s' design of rewarding years of service, should be overhauled and replaced with one that recognised hard work and merit instead, he said.

He also called for annual fitness tests to be brought in, with those who repeatedly fail at risk of being docked almost £3,000 and, in the most extreme cases, sacked for unsatisfactory performance.

A new educational requirement should also be brought in, with applicants needing the equivalent of three A-levels at grades A to C, along with direct entry for civilians into the ranks of inspector and superintendent.

The review also said the starting salary for police constables should be cut from the current £23,500 to £19,000 for someone with no police-related experience.

Among the 121 recommendations, the report said there should be higher pay for more demanding jobs, pay linked to skills and performance rather than length of service, and an allowance for working unsocial hours, defined as outside 8am to 6pm.

It also called for the pension age for officers to be raised to 60, in line with Lord Hutton's recommendations.

But previous attempts to overhaul police pay and conditions have failed in the face of fierce opposition from rank-and-file officers.

The last review, carried out in June 1993 by Sir Patrick Sheehy under then-home secretary Kenneth Clarke, recommended abolishing jobs for life, introducing fixed terms of service and scrapping overtime payments.

But most of the recommendations were never implemented after a high-profile campaign by the Police Federation.

Labour home secretary Jacqui Smith also tried to save money in 2008 by rejecting a recommended pay increase - but again was forced to back down after officers marched in London.