Britain cannot afford another stimulus package, the governor of the Bank of England warned on Tuesday, in a boost for Angela Merkel and other European leaders who are urging such caution ahead of next week’s Group of 20 summit in London.

The comments of such an influential figure as the Bank governor make it difficult for Gordon Brown, the UK prime minister, to insist on an expansionary Budget in late April and to press other European countries into agreeing further tax cuts or public spending increases at the G20 summit.