Businesses that made a profit during the Covid crisis could bear the brunt of a hefty rise in corporation tax over future years as Rishi Sunak considers plans to give loss-making firms a higher rebate.

Treasury officials are understood to have held discussions with tax experts about an expansion of the so-called loss carry-back rules, which allow firms which previously made a loss to cut their tax bills when they return to profit.

The move would sweeten the pill of an expected rise in corporation tax from 19pc to 25pc next week as the Chancellor begins the task of repairing the public finances.

It would mean firms hit with the highest losses - such as fashion chains and airports - could reduce their tax bills for years to come. By contrast, companies which made a profit during the crisis would be unable to cut their future tax bills in the same way.

Firms can only carry back losses for a year. The plans being considered would extend this to three years, allowing them to claim bigger rebates.

A source said: “We have had discussions with them over the types of firms which would benefit. The one big advantage of this is that it would benefit these companies now."

The proposed scheme echoes the measure introduced by Alistair Darling in November 2008 in the wake of the financial crisis, which was targeted at smaller businesses.

A revived version could potentially be open to firms of all sizes, and targeted at industries hit hardest.

It is understood that the extended carry-back would be an attractive option as it targets support to firms with a previous record of profitability, helping avoid the risk of propping up unsustainable business as the UK economy moves from crisis to recovery.

The CBI argued for the move before Christmas in evidence to the Treasury Select Committee. Its head of tax Annie Gascoyne told MPs that the loss carry-back would give firms a vital cash injection to grow post-crisis.

Chris Sanger, head of tax at EY, said: “If you're incurring losses and you've got the history of taxable profits, then the banks can be pretty assured that you're going to be able to get relief for those losses as you incur them. This would be quite an attractive move in order to help those kind of businesses move forward.”

Ministers are also considering a shake-up of research and development (R&D) tax credits to help spur investment by firms after the pandemic.

A source with knowledge of the discussions said officials are mulling an expansion of the tax relief to cover a wider range of spending, including costs on data and cloud computing.

A consultation was held last year to look at making R&D tax credits reflect modern trends, but industry leaders are also pushing for a wider overhaul to boost investment.

Dom Hallas, head of start-uip industry group Coadec, said: “R&D tax credits are already critical for the growth of innovative businesses, with 69pc of startups saying they are very important for their early stage growth."

He said the relief must to be brought up to date to help turbocharge R&D spending.

A report by eight trade bodies earlier this month described the tax relief as outdated and said that overhauling it to include more capital spending would provide a £4bn boost to the economy.

The Treasury declined to comment.