Margaret Hodge MP has said the Treasury "fell down" in its responsibility of monitoring the body which controls the Queen's finances, as the Paradise Papers leak continues to have a major political impact.
The British monarch was dragged into the scandal after the leak of 13.4 financial documents showed the Duchy of Lancaster made offshore investments to accounts in the Cayman Islands and Bermuda across 2004 and 2005.
The Queen does not manage investments made by the Duchy, and pays tax voluntarily on her income.
Hodge, the MP for Barking and the former Chair of the Public Accounts Committee, said the furore was the fault of both the Queen's advisors and the Treasury.
She told Julia Hartley-Brewer: "The Treasury is responsible for monitoring the Duchy of Lancaster and the Duke of Cornwall’s estate.
"I think they fell down on the job too. The argument goes two ways.
"Both her advisors should have done more, we should have more transparency, and what on earth were the treasury officials up to, that they allowed the advisors to invest in overseas territory?"
She made it clear what the Government needs to do to combat issues posed by offshore tax havens.
"This is an intolerable practice and frankly, as far as the UK Government is concerned, I’m fed up of the rhetoric, the good intentions.
"I want them to act. I don’t want a public inquiry, just act.
"All British people, whatever their politics, wherever they live, whatever their age or gender, I think there would be huge support if we got tough on our taxes.”