Giving evidence to the committee on standards in public life, the parliamentary standards commissioner, Philip Mawer, requested more powers to summon MPs to give evidence and called for access to documents when investigating an MP's financial affairs.

However, last week senior MPs giving evidence to the committee, which is investigating how successful the self-regulation of parliament is, claimed that no more powers were needed.

The committee, chaired by Sir Nigel Wicks, questioned the independence of the commissioner.