Shadow chancellor George Osborne has written to Alistair Darling accusing him of damaging the UK economy.
Osborne told the chancellor that Conservative policies would restore competitiveness and prevent companies leaving the UK.
He pointed to the news that three large companies have announced they are moving abroad for tax reasons as proof that Darling needs to act.
The letter said this was "further evidence of the damage done to the UK by the confusion you have caused in the last year over the future of our business tax regime".
He said the UK had "some of the highest corporate tax in the EU", and urged Darling to cut the main corporation tax rate from 28 per cent to 25 per cent.
Osborne also called for the chancellor to simplify the rules regarding government capital allowances and bring about a "permanent simplification of the tax system".
"With companies leaving Britain, weakening an already ailing British economy, I urge you to adopt our proposals in order to restore our competitiveness and help prevent any more companies from deciding to leave the UK," he wrote.
