Gordon Brown is expected to announce March 24^th as the day for the pre-election Budget as the campaign accelerates towards a May 6^th showdown. The Prime Minister will also place his stewardship of the economy at the heart of his election drive, despite overseeing the longest and deepest recession since the Second World War. The economy suffered a major setback yesterday after a fresh warning on the deficit, a weaker pound, and the sharpest fall in exports in more than three years heightened fears that Britain is in store for a double-dip recession. The pound closed below $1.50 for the first time in a week after ratings agency Fitch warned the Government's timetable to reduce Britain's record deficit was "frankly too slow". Brian Coulton, the agency's head of sovereign ratings, said Britain's fiscal outlook has "clearly deteriorated pretty sharply" over the last year and had seen the most rapid rise in the ratio of public debt to gross domestic product of any AAA-rated country.