Thousands of retiring soldiers will be encouraged to become reservists as ministers rebrand and beef up the Territorial Army.

Defence Secretary Philip Hammond is to announce today that he wants the new force to be called the Army Reserve.

The Coalition wants to double the number of part-time soldiers to 30,000, at the same time as it cuts regular Army personnel from 102,000 to 82,000.

Ministers want to target the 18,000 regulars they say leave the Army every year.

They warn little or no records are kept and that a valuable resource is being lost. They want to develop incentives for them to join the Reserves and make it easy for them to transfer across.

A Government source admitted there would be limits to how many could join the new force, because of factors such as age and fitness, but said it was wrong they were not being targeted at the moment.

Mr Hammond will outline plans to create a fully integrated force of regulars and reservists, able to deploy as units.

To help with their new role, the number of training days will be increased from 35 to 40 a year.

Employers will also be given more notice ahead of mobilisations. The Ministry of Defence is spending £1.8 billion over the next decade to give reservists better training, new vehicles and the same uniforms as the regular Army.

Jim Murphy, Labour's Shadow Defence Secretary, said: "If more is going to be asked of reservists, ministers must provide more support. Anti-discrimination legislation, improved pre-deployment training and better mental healthcare are vital."