Boris Johnson will face calls for a public inquiry into allegations of Tory sleaze as MPs consider how to clean up Westminster following the Owen Paterson row.
Labour leader Sir Keir Starmer said the Prime Minister should apologise to the nation and “clean out the filthy Augean stable he has created”.
The Commons will spend three hours hearing an emergency debate on the situation, despite ministers seeking to dismiss the row as a “storm in a teacup”.
The Liberal Democrats, who secured the debate, have called for a statutory public inquiry into sleaze and corruption allegations.
The inquiry, which would have the power to summon witnesses and take evidence under oath, would examine not only the Paterson row but also the awarding of coronavirus contracts, whether Mr Johnson’s holidays in villas provided by friends were properly declared, and how the refurbishment of his Downing Street flat was funded.
A debate was granted last week by Speaker Lindsay Hoyle following Tory attempts to block an immediate 30-day suspension for Mr Paterson over an “egregious” breach of lobbying rules.
Conservative MPs were ordered instead to back the creation of a Tory-led committee to look again at Mr Paterson’s case and the whole standards system.
But after a backlash the Government performed a U-turn and Mr Paterson subsequently quit as an MP, leaving what he called the “cruel world of politics”.
Reports at the weekend suggested the Speaker may put forward his own proposals for reform of the standards process in an effort to take some of the increasingly bitter politics out of the row.
Ahead of the emergency debate, Sir Keir said the Prime Minister must publicly confirm that former Cabinet minister Mr Paterson will not be nominated for a peerage.
Downing Street sources have indicated there is no intention for Mr Paterson to be given a seat in the Upper Chamber.
Sir Keir will lead the debate for Labour, but Mr Johnson is expected to hand Commons Leader Jacob Rees-Mogg the job of representing the Government.
“Boris Johnson needs to attend this debate, answer for his mistakes, apologise to the country and take action to undo the damage he has done,” Sir Keir said.
“The country is yet to hear a word of contrition over his attempts to create one rule for him and his friends and another for everyone else. He must now come to the House and say sorry.”
The Liberal Democrats pushed for a change to Commons rules to prevent any MPs being investigated by the Parliamentary Commissioner for Standards from voting on or proposing amendments to motions related to disciplinary issues.
Lib Dem chief whip Wendy Chamberlain said it was “the equivalent of defendants in a court case also taking part in the jury”.
She added: “Time and again Government ministers have refused to properly investigate allegations of sleaze, failed to declare relevant meetings and donations and tried to rig the system to cover their own backs.
“We need an independent public inquiry, with the powers and resources to get to the bottom of this Conservative sleaze scandal.”
Tory MPs, who have been contacted by furious constituents about the situation, remain angry at the handling of the Paterson case and relations have not been helped by Environment Secretary George Eustice’s claim that it was a “Westminster storm in a teacup”.
High Peak MP Robert Largan, one of the new generation of Tory MPs elected in 2019, criticised Mr Eustice’s attempt to downplay the row, telling Times Radio: “I don’t think it’s very helpful to say, ‘oh, it’s just a storm in a teacup’.
“In my view this was something that we got badly wrong and they need to fix it.”
Another 2019 Tory MP told the PA news agency that Mr Eustice’s comments were “complete nonsense”.
The MP said: “They need to get a grip and understand that this isn’t the way the world works any more. It might have been 20 years ago or something like that, but people expect – rightly so – the highest standards.”