The FTSE 100 was called to open around 30 points lower, with Chancellor Rachel Reeves due to deliver her first Budget after Prime Minister’s Questions.

Steve Clayton, head of equity funds at Hargreaves Lansdown, said: "Retail investors are bracing themselves ahead of what is widely expected to be one of the most significant Budget days of recent years. Rachel Reeves has had only a few months to determine the magnitude of the UK’s fiscal challenges, let alone work out the measures needed to correct the course and enable the new Government to start to execute its plans.

"Changes to pensions, capital gains tax, inheritance tax and employers NI have all been mooted in the press.

"The headline numbers look likely to be big, with estimates of the sums needing to be raised having risen to as much as £40bn."

In corporate news, GSK reported a 2% increase in constant exchange rate sales in its third-quarter results, to £8bn, with strong specialty medicines growth offsetting a 15% decline in vaccine sales, affected by shifts in US vaccination priorities.

The FTSE 100 pharmaceuticals giant said that while total operating profit fell 86% due to a £1.8bn Zantac settlement charge, core operating profit and earnings per share each rose 5%, driven by specialty medicines and cost management.

It reaffirmed its 2024 guidance, expecting turnover growth of 7% to 9% and mid-range core profit growth, with a third quarter dividend of 15p and a projected full-year dividend of 60p.

Next lifted its guidance for both the crucial fourth quarter and the full year, after the recent cold snap caused sales to surge.

Updating on trading, the blue chip retailer said full price sales surged 7.6% in the 13 weeks to 26 October, well ahead of the 5% uplift it had forecast.

Next attributed the better-than-expected performance to the arrival of colder weather this year, which compared favourably to last year’s unusually warm September and early October.

As a result, Next lifted guidance for fourth-quarter full price sales, to 3.5%, and full-year profits and sales.

It now expects 2024/25 sales to come in at £5.02bn, compared to its previous forecast for £4.98bn, with pre-tax profits topping £1bn, at £1.005bn. That would be an 9.5% increase on the previous year.

Total group sales - which include markdowns and subsidiaries - are forecast to be £6.27bn, up 7.4% year-on-year.

Prior to Wednesday’s update, Next had expected full-year pre-tax profits to come in at £995m on sales of £4.98bn.