The speaker of Parliament is being urged to keep MPs on a tighter leash.

Labour and National MPs are being roundly criticised for their behaviour during yesterday's debate on events at Christmas Island.

John Key accused Labour of siding with convicted rapists and murderers, and several Labour MPs walked out in protest.

Victoria University governance expert Chris Eichbaum told Tim Wilson on KPMG Early Edition speaker David Carter needs to be tougher and more even-handed.