Billionaire businessman Gopichand Hinduja, chairman of the Hinduja Group.Aaron Chown | Pa Images | Getty ImagesLONDON — Britain’s wealthiest man, Gopichand Hinduja, condemned the U.K.’s departure from the European Union, but threw his backing behind Prime Minister Rishi Sunak’s ability to revive the country’s ailing economy.The Indian-born British billionaire, who is chairman of Indian conglomerate the Hinduja Group, said that the U.K.’s efforts to forge new trade partnerships would provide a much needed boost for the country and reestablish Britain as an “excellent” place to invest.”The step taken of Brexit was not good for the U.K.,” Hinduja told CNBC’s Tanvir Gill in London on Monday. Britain voted to leave the European Union in 2016 and formally exited the bloc at the end of Jan. 2020.”To correct it, now they have gone to these 11 countries. This will help,” he said, in reference to deals including the recently signed Comprehensive and Progressive Agreement for Trans-Pacific Partnership.None of those partnerships will be more valuable to the U.K. than its forthcoming free trade arrangement (FTA) with India, according to Hinduja.”The biggest help the U.K. can get is from India, because India’s economy, by 2027, will be the third largest in the world,” he said.Hinduja said he had revised forward his growth projection for India’s economy — currently the world’s fifth largest — from 2030 based on his instincts and experiences.Britain and India last week concluded their 11th round of negotiations for a free trade agreement, which has faced several setbacks amid differences on some major tariff lines and investment protection rules.Hinduja, who is not involved in negotiations, said that bureaucracy had been the “biggest problem,” but he added that the ultimate benefits for the U.K. would be wide-reaching.”There will be a lot to be done in technologies, in infrastructure, in health, in education and, especially, in defense side the U.K. is very interested,” he said.Long-term investors in the U.K.The 83-year-old businessman — whose business spans sectors including IT, property, energy and healthcare, earning him and his family a net worth of $35 billion in 2023 — said that he had not been deterred from investing broadly in the U.K., despite recent economic weakness.”So far as our group is concerned, we have been in many different businesses in the U.K. and we are long-term believers. We don’t go on short-term,” he said.”There is not a single business in our group which has closed or has not been successful,” he added.The U.K. economy has been sluggish over recent years, growing just 0.1% in the first quarter of 2023, as rising interest rates, stubbornly high inflation and a chaotic so-called “mini-budget” have weighed heavily.Hinduja said that the softness was largely “outside of the control” of the government, citing events including Russia’s invasion of Ukraine, and insisted that Conservative leader Sunak was on the “right track” to raise the outlook.”There’s steps which the Prime Minister has taken,” he said, referring to Sunak’s five-point economic plan. That includes plans to halve inflation, grow the economy, reduce debt, cut NHS waiting lists, and curb immigration.”He’s going on the right track. He himself is a financial person and he is taking all the steps, but he has many challenges. It’s not an easy task for him,” he said.The incumbent Tory party is currently seen around 17 points behind the opposition Labour Party in the polls as public sentiment has shifted following a 13-year stronghold. The next general election is scheduled to be held no later than Jan. 28, 2025.