Five Conservative MPs breached the code of conduct over an attempt to influence legal proceedings, a standards committee has found.
Theresa Villiers, Natalie Elphicke, Sir Roger Gale, Adam Holloway and Bob Stewart wrote letters regarding ex-MP Charlie Elphicke, who was convicted of sex offences.
The letters on Commons notepaper were addressed to senior judges.
Three of the MPs could be suspended from Parliament for one day
Ms Villiers, Mrs Elphicke and Sir Roger face suspension, while Mr Holloway and Col Stewart have been told to apologise by the Commons Standards Committee.
All five wrote to senior members of the judiciary raising concerns that a more junior judge was considering publishing character references provided for Mr Elphicke.
Mr Elphicke was jailed for two years in September 2020 after being convicted of three counts of assault against two women.
The committee said the MPs' letters amounted to "an attempt improperly to influence judicial proceedings".
It said that "such egregious behaviour is corrosive to the rule of law and, if allowed to continue unchecked, could undermine public trust in the independence of judges."
And it found the MPs' behaviour had "caused significant damage to the reputation and integrity" of the House of Commons.
The committee said of the three MPs recommended for suspension, two had "substantial legal experience" while the third, Sir Roger, is both the longest standing of the group and "still does not accept his mistake".