It was confirmed earlier in April the Prime Minister, along with Chancellor Rishi Sunak, would be fined by the Metropolitan Police in relation to its investigation into lockdown-breaking gatherings at Downing Street.
Subsequently last week MPs approved the Privileges Committee launching its own inquiry once the police have finished their investigation into the gatherings.
She said: “I am in favour of the matter being referred to the Privileges Committee, and I remained in the chamber to vote accordingly, but the House didn’t divide, and the matter went through on the nod.
“I continue to support Boris Johnson and the work our Government is doing to level up the north of England in accordance with manifesto commitments, despite the global pandemic and other challenging international circumstances.”
The Privileges Committee will investigate whether Mr Johnson is in contempt of Parliament for misleading MPs with his repeated denials of lockdown-busting parties in Downing Street.
It adds to inquiries being conducted by the Metropolitan Police and senior civil servant Sue Gray.
So far the police have announced they have issued at least 50 fines as part of their investigation.
Tory MPs had initially been ordered to back a Government amendment which would defer any decision on referring the matter to the committee until after the conclusion of the Met Police inquiry.
But in a late U-turn shortly before the debate began, they were given a free vote.