When the House of Lords hits the headlines it generally spells trouble. Very often it is trouble for ministers, as the UK’s senior legislative chamber has a habit of knocking down government plans in a way that dissidents in the executive-dominated Commons can only envy. But this week, the stories have been bad news for the upper house itself.

An investigation by The Sunday Times alleged that four Labour peers would accept payment in return for trying to influence legislation. All the peers – Lord Taylor of Blackburn, Lord Truscott, Lord Snape and Lord Moonie – deny acting improperly. But the claims have already prompted closer public scrutiny of what peers do all day. The extent of paid interests in the upper house sits ill with the looseness of the Lords’ code of conduct.