Angela Rayner has warned that Boris Johnson's lies will "plague parliament for years to come" if he doesn't resign.
The Deputy Leader of the Labour Party was on ITV's Good Morning Britain today, where she discussed the Prime Minister's apology, which he made to the House of Commons yesterday after he received a fixed penalty notice over the Partygate scandal.
Ms Rayner explained how she felt the whole situation could have been "dealt with very quickly had the Prime Minister told the truth", as she warned there could be lasting effects on parliamentary and the UK democracy if Mr Johnson is allowed to stay.
Speaking on the ITV show, she said: "Nobody's indispensable. This isn't just about the Prime Minister, this is about the ongoing integrity of the ministerial office. This will damage our democracy if the Prime Minister is seen to have broken his own laws and get away with it. It basically tears up the ministerial code and says you can lie to parliament and get away with it.
"Now this has long term repercussions for the UK and won't go away. This could have been dealt with very quickly had the Prime Minister told the truth and had he have fessed up right at the start that he did break his rules."
Ms Rayner says Mr Johnson's behaviour crosses a red line, as she urged for Mr Johnson not to "get away" with what happened.
"This isn't just about him breaking his rules, it's about a Prime Minister in office breaking his rules and then lying to the public and parliament and get away with it. It will have implications for us longstanding into our democratic processes," she added.
"I think it's a red line and it will plague our parliament for many decades to come if the Prime Minister is seen to be able to get away with it. If he's can lie about that quite frankly, he can lie about other things aswell."
In his speech to the Commons, Mr Johnson apologised over 90 times.
"Let me begin in all humility," he said, "I paid the fine immediately and I offered the British people my apology. I acknowledged the hurt and the anger, and that people have the right to expect better from the Prime Minister. I repeat that again to the house."
Insisting it didn't "occur" to him that he was breaking the law, he added: "That was my mistake and I apologise for it unreservedly."
