The Speaker of the House of Commons said it was “totally unacceptable that we go around the world telling everyone” about “big” new policy announcements instead of giving the information to MPs first.
Sir Lindsay also questioned whether MPs would have to bother attending the House to hear Ms Reeves present her first budget on Wednesday, given that “we’ve all heard it”.
Last week Ms Reeves signaled she would rewrite the way national debt is measured.
In a round of interviews while attending the International Monetary Fund meeting in Washington, Ms Reeves confirmed a technical change to how she will measure progress against the debt management target.
Ms Reeves is expected to use the budget to open the door for the government to spend billions more on long-term infrastructure, such as replacing dilapidated buildings with public sector estates.
Sir Lindsay, making a statement, told the Commons: “In interviews with the media last week, the Chancellor announced that he intends to introduce changes to the fiscal rules relating to the funding of day-to-day spending through tax receipts and to the measurement of public debt.
“These are important new policy announcements with significant and far-reaching implications for the government’s fiscal policy and public finances.
“It is obvious to me that this should have been done in the first place in this room, not in front of the world’s media.
“This principle is clearly and unequivocally stated in paragraph 9.1 of the Ministerial Code. Although this could hardly be described as a leak – the chancellor herself has given interviews on the record and on camera – premature disclosure of the contents of the budget has always been regarded as the ultimate discourtesy to the House.
“Indeed, I still think of him as such.
“I am very, very disappointed that the Chancellor expects the House to wait almost a whole week to hear her repeat these messages in Wednesday’s Budget Statement.”
Sir Lindsay said he had “always defended” MPs’ right to be the first to hear important government policy announcements, adding: “Ministers should expect to face appropriate, sustained scrutiny when these announcements are made by elected members of this House, and not from American news channels.
He noted Finance Minister Darren Jones’ statement to the House on “fiscal rules” on Monday, adding: “Maybe it’s not a coincidence.
“Honorable members may be wondering how they are going to get a seat on Wednesday (for the Budget) – frankly, the way it is going, it won’t be necessary, we’ve all heard it. It is not acceptable, I do not want it to continue and I want to treat this House with the respect it deserves.”
Sir Lindsay added: “It is totally unacceptable that we go around the world telling everyone and not these members. They were elected by the voters of this country and deserve to be treated better.
He went on to mark Labor when in opposition it complained about the previous Tory government behaving in a similar way, adding: “Get your act together, all parties, treat members with respect.”
The Prime Minister’s official spokesman, responding to criticism from the Speaker of the House of Commons, told reporters: “I don’t want to comment on parliamentary matters, but it is quite routine for the Government to make announcements in the run-up to budgets and spending reviews.
“But obviously we will also ensure that Parliament has all the time it needs to consider the measures clearly.
“The chancellor will be before parliament on Wednesday and indeed there will be days of budget debate afterwards where parliamentarians will be able to scrutinize the budget measures.”
In a statement to the House of Commons, Mr Jones set out changes to the fiscal rules, known as “the stability rule that we will pay for all day-to-day spending on public services from receipts” and “the investment rule that will get the debt reduced as part of our economy’.
Finance committee chair Dame Meg Hillier asked Mr Jones to explain “how the railings will work between the National Infrastructure and Services Transformation Authority, the Office for Value for Money and the National Audit Office – what roles each will play to ensure , that we calm the markets so that the autumn sniffles do not turn into winter cold”.
Mr Jones replied: “The National Infrastructure Strategy will bring together all the infrastructure and major projects set by Whitehall departments in one place, along with economic infrastructure assessments for the first time.
“This will inform the multi-year spending reviews, which will now overlap.”