Britain risks plunging from the world’s fifth-biggest economy to seventh-largest next year, as sluggish growth and Brexit fears allow France and India to jump ahead, a new report suggested.

The UK’s economy is expected to grow by 1.6% next year, the study by accountancy firm PwC said, assuming the country avoids a no-deal scenario.

But even with that assumption, the figure is lower than France, whose economy is expected grow by 1.7%, and India, at 7.6%.

“The UK and France have regularly alternated in having the larger economy, but subdued growth in the UK in 2018 and again in 2019 is likely to tip the balance in France’s favour,” PwC economist Mike Jakeman said.

The ranking is based on the size of national economies in US dollars.

Britain’s economy slowed and the value of the pound slumped after the 2016 Brexit referendum decision to leave the EU.

“India is the fastest-growing large economy in the world, with an enormous population, favourable demographics and high catch-up potential due to low initial [gross domestic product] per head,” Jakeman added.

“It is all but certain to continue to rise in the global GDP league table in the coming decades.”

The PwC report came as five of Britain’s leading business groups warned of the risks posed by an increasingly possible no-deal Brexit.

The British Chambers of Commerce, CBI, EEF, Institute of Directors and Federation of Small Businesses said time was running out on avoiding the “horror” of no-deal.

Meanwhile, the government on Tuesday launched a £2bn contingency package aimed at preparing the nation for crashing out of the EU.