Hundreds of thousands of Britons could be forced to pay up to 39 per cent in tax on the profits of their investments, as Chancellor Rachel Reeves mulls ways to fill the “£22billion black hole”. Treasury officials are testing a range of 33 per cent to 39 per cent capital gains tax rates in modelling being reviewed by the Chancellor, The Guardian reports. Around 350,000 people pay capital gains tax, which is levied upon the sale of assets, including second homes and shares. The gain made on the asset is taxed, currently at a significantly lower rate than wages. Higher or additional rate taxpayer…