Rules which aim to prevent MPs from lying in Parliament “will not hold”, ministers have been warned.

Labour chair of the Commons standards committee Chris Bryant also said there was “no justice” in throwing MPs out of the chamber after correctly accusing others of lying.

The Commons also heard that a new MP does not “want to risk being an MP any longer” due to the potential reputational damage caused by the recent lobbying scandal.

Opening a debate on reviewing the code of conduct for MPs, Mr Bryant said: “If a member lies and refuses to correct the record, and the public can plainly see that the member has lied, what do we do?

“Force the member who calls it out to add the word ‘inadvertent’ when we know perfectly well that the member that used the word ‘inadvertent’ didn’t mean it at all, so we are forcing them to lie?

“Should we throw the member out of the chamber if they refuse? That is what the rules say we should do – where is the justice in that?”

Labour MP Mr Bryant’s call for reform comes after SNP Westminster leader Ian Blackford left the Commons chamber on Monday after accusing Boris Johnson of having “wilfully misled” MPs over the Downing Street party allegations.

Commons speaker Sir Lindsay Hoyle had asked Mr Blackford to withdraw the remark and accept the Prime Minister had inadvertently misled MPs, or risk being thrown out of Parliament.

Mr Bryant continued: “I fear these rules, written at a time when a member could not imagine anything worse than having their honour traduced in public – and frankly, honour isn’t what it used to be – I don’t think this rule will hold as it presently is forever.”

Asking for MPs for their opinions on how standards should be reformed in light of the recent lobbying scandal, Mr Bryant suggested a ban on all posts “involving parliamentary advice”.

He also called for Government ministers to have to register all financial interests with parliament, as well as with their ministerial register of interests.

Mr Bryant said: “Ministers, who of course by definition are a member of this House or of the other, are not required to register hospitality received in a ministerial capacity with the House, which means they are held to a lesser degree of transparency than the rest of us. That cannot be right.”

Conservative former minister Dame Andrea Leadsom shared worries of an MP concerned that their post risked their future reputation.

Dame Andrea said: “I had a new colleague come to me and say, ‘I spent 25 years working in the public sector, I don’t want to risk being an MP for any longer because of the way, if you make a mistake, your name, your good reputation, will be taken through the gutter, you will never live it down’.

“So what we’ve done is slightly created a system of disaster, and it’s something our constituents can’t rely on either, so what I’d like to see is a big review, a review of what is an MP there for, how we actually help MPs and those who work for us to do their job better, and what can we do to actually make people proud of their MPs and their parliamentarians.”

Commons leader Jacob Rees-Mogg agreed there was “widespread consensus” on banning MPs from holding second jobs as parliamentary advisers to outside companies, and acknowledged there was a “knotty question” about how second jobs should be policed in future.

However, Mr Rees-Mogg disagreed with calls for ministers to have to register all hospitality gifts in the same way as other MPs, describing some of these events as “duties” Government representatives have to undertake.

The Commons leader said: “What ministers do may be duty rather than pleasure, whereas members don’t have to accept invitations in that sphere or certainly not normally.”