MPs who have committed historic crimes or fiddled their expenses would be let off the hook under the Coalition Government's "recall" plans, Labour has warned.

The proposals are designed to allow voters to sack disgraced MPs between general elections.

But the proposed changes have faced claims that they are too weak and would allow MPs to protect their own.

Now Labour have tabled a series of amendments designed to ensure expenses fraud and historic crimes are included.

The party is concerned that politicians whose crimes emerge only after they were elected would currently escape.

They point to the case of former SNP MSP Bill Walker, jailed last year after he was convicted of domestic abuse stretching back decades.

However, under the amendment, the recall process would not apply if an MP has been convicted of a crime before he or she was elected and which voters knew about when they cast their ballots.

A separate amendment would also ensure the recall process automatically starts if an MP is convicted of abusing the parliamentary expenses system.

It follows the widespread public outrage over the 2009 expenses scandal, which saw former Livingstone MP Jim Devine, among others, sent to jail.

Under the recall process a petition would be opened in the MPs constituency.

If enough voters sign it they can trigger a by-election.

Thomas Docherty, Labour's shadow deputy leader of the House, said any MPs found guilty of expenses fraud should be subject to recall.

Both David Cameron and Nick Clegg have recently suggested that they would back moves to strengthen the recall proposals.