Prison sentences are to be linked to whether there are enough places in jail, under government proposals.

For the first time judges will be expected to consider the state of prisons and the numbers already in them when deciding if a criminal should be jailed or given a community sentence.

The move, which has the full support of Lord Woolf, the lord chief justice, is part of the Management of Offenders and Sentencing Bill.

The legislation also includes plans for a huge increase in the maximum fines magistrates can impose.

David Davis, the shadow home secretary, slammed the plans.

"For the first time in British history, sentencing will be decided by economics rather than the merit of an individual case," he said.

"It is a disgraceful violation of our criminal justice system and will lead to thousands of criminals getting shorter sentences, or no sentence at all, because the government has failed to provide enough prison places."