"On paper, this approach appears to be far more aggressive than the BoE's current objective, " said Jane Foley, a senior currency strategist from Rabobank.

BBC: Mark Carney suggests targeting economic output

Despite these moves, official recognition of a shift away from the inflation target would be "a huge political and psychological step", Jane Foley said.

BBC: Mark Carney suggests targeting economic output

"The statement from the G20 last night may have taken the edge off the current bitter market sentiment, but the reassurances from the finance ministers lack substance, " said Jane Foley at Rabobank.

BBC: IMF promises decisive action for eurozone debt crisis