Britain plans to make a fresh attempt next year to persuade the European Union to step up economic sanctions against Robert Mugabe’s regime in Zimbabwe after it bluntly declared for the first time that he could no longer be part of any political solution to the country’s crisis.

Mr Mugabe was an “absolutely impossible obstacle” to achieving a power sharing agreement in Zimbabwe, the government said, echoing US criticisms. Officials said London would press to extend the list of senior members of the Mugabe regime who were subject to sanctions.