Margaret Hodge, who chairs PAC, said: "Promoters of 'boutique' tax avoidance schemes like the one brought to our attention by the case of Jimmy Carr, are running rings around HMRC.
She added that schemes which exploit loopholes within the system are being taken advantage of.
"It has allowed a system to evolve where the dice are loaded in favour of the promoters of tax avoidance schemes," she said.
More top news
On Monday afternoon, numerous Facebook posts claimed a silver Mini had been stolen from the town with a girl in it.
Top temperatures 10 Celsius (50F).
Britain and the European Commission reached agreement on a transition deal which will allow talks on the future trade relationship.