Corporation tax is scheduled to be reduced from 19% to 17% from 1 April 2020.
However, in a speech to the CBI on 18 November Boris Johnson announced that, if elected, the Conservative Party would keep the rate at 19% to provide an extra £6 billion for the NHS.
Despite Jeremy Corbyn telling the CBI that the Labour party is not anti-business the party have previously announced that they would reverse the recent cuts in corporation tax. Note that the rate of corporation tax was 28% back in 2010 at the end of the last Labour government.