After days of confusion, Britain’s government said on Monday that the date for its next fiscal policy announcement would be moved up nearly a month and that it would provide, at the same time, a much-anticipated independent assessment of the policies’ impact on the nation’s economy and public finances.

The chancellor of the Exchequer, Kwasi Kwarteng, said he would publish his “medium-term fiscal plan” on Oct. 31, which would show how the government, under the new prime minister, Liz Truss, would bring down debt levels despite large spending plans and tax cuts that would be funded by borrowing.

New economic and fiscal forecasts from the Office for Budget Responsibility, a government watchdog, are to be published the same day.

The move is aimed to reassure financial markets and the public of the new government’s fiscal credibility. Its first major economic announcement, a speech by Mr. Kwarteng on Sept. 23, was dominated by unfunded tax cuts at a time of high inflation, and it quickly sent markets into a tailspin: The British pound hit a record low against the dollar, and turmoil in the bond market led to higher mortgage rates and intervention from the Bank of England to protect pension funds.

Since then, the government has canceled its plan to abolish the top income tax rate for the highest earners — the most surprising tax-cutting measure announced last month — and tried to restore its fiscal credibility, while maintaining its commitment to an agenda of using tax cuts and deregulation to speed economic growth.

Part of this rehabilitation effort included a promise to publish a more detailed fiscal plan focused on reducing debt and provide an independent analysis by the Office for Budget Responsibility. But the date was set for Nov. 23 — too long to wait, said fellow Conservative Party members, opposition lawmakers and investors.

Last week, it was widely reported that the date would be moved forward, and Mr. Kwarteng denied this. On Monday, he confirmed that the announcement would indeed arrive on Oct. 31.

Two weeks ago, in the immediate aftermath of Mr. Kwarteng’s policy speech, the pound plummeted to $1.035 and speculation grew that it could reach parity with the dollar. The cancellation of the top tax rate cut, which the government argued had become a distraction from its overall growth plan, helped the currency rebound a bit.

But that recovery has stalled. On Monday, the pound was trading around $1.10 amid skepticism that the government’s plan would expand the economy as promised, and that instead large public spending cuts would be necessary.

Fitch Ratings said on Monday that it expected the British economy to contract 1 percent next year, after “extreme volatility” in British financial markets and the prospect of “sharply higher” interest rates. Last month, it forecast a 0.2 percent decline for next year.

“Rising funding costs, tighter financing conditions, including for mortgage borrowers, and increased uncertainty will outweigh the impact of looser fiscal policy” next year, analysts at the ratings agency wrote. They expect Britain’s economy to enter a recession in this quarter. The agency has already changed its ratings outlook for Britain to negative.

That was just one of many rebukes of the government’s plans. For example, the International Monetary Fund encouraged the government to re-evaluate the tax cuts, which it said would increase inequality.

But Ms. Truss, seeking to reverse years of sluggish growth and weak productivity, has been clear that she wants to run the economy differently than her predecessors. One early decision was to fire the top civil servant in the Treasury, Tom Scholar, a move that rattled some analysts. On Monday, the government announced his successor, James Bowler, who will transfer from the international trade department but spent two decades at the Treasury previously.

Even as the government makes conciliatory moves, there are signs of distress in financial markets. On Monday, the Bank of England said it would expand its intervention in the bond market. The bank will increase the size of the daily auctions in a bond-buying program that was set up to support pensions funds, after tumult in this market threatened Britain’s financial stability.

Over the last eight trading days, the bank bought only about 5 billion pounds of long-dated government bonds in total, despite setting a limit of £5 billion a day. With markets wondering what will happen when the bond-buying operation ends on Friday, the central bank announced that it would expand its support. As well as increasing the auction sizes, it will set up a new collateral facility to try to ease liquidity problems faced by the pension funds. That facility will continue beyond this week.

The announcement appeared to do little to ease the markets. On Monday, Britain’s bond prices kept falling, while the yield on 30-year bonds rose to 4.72 percent, once again approaching highs seen during the worst of the bond rout after the last fiscal statement.