The chancellor yesterday added to speculation that he will deliver a "not yet" verdict on the single currency.

Whilst he blamed the eurozone for Britain's sluggish growth he announced two significant euro-friendly policies - a shift to fixed rate mortgages and a shift in inflation calculations - which added to suspicions that he will deliver an equivocal assessment when he reports on his five tests.

Brown also confirmed that the eagerly awaited announcement will come "by the first week of June".