The chancellor, George Osborne, and the governor of the Bank of England, Mark Carney, are to miss next weekend's meeting of G20 central bank governors and finance ministers to ensure they are in the UK for the outcome of the Scottish referendum.

Carney's travel plans would have required him to be in Cairns, Australia, from Wednesday until Sunday to attend a crucial gathering of G20 finance ministers and central bank governors. His decision was taken earlier this week, when he also told the Treasury select committee that the Bank of England had made contingency plans in the event of Scotland voting to break away from the rest of the UK.

Osborne is understood to have taken the decision some time ago not to fly to Australia at all.

The changes to their schedules were revealed as a Guardian/ICM poll put the yes vote just two percentage points behind those supporting the union.

Carney will still fly to Australia to chair the Financial Stability Board, a powerful group that coordinates international regulation, on Wednesday but return by Thursday night. His place at the G20 meeting will be taken by Sir Jon Cunliffe, deputy governor for financial stability.

The Bank of England said: "The final decision was taken this week. It is just prudent planning, and you would expect the central bank governor of the United Kingdom to be here for an occasion such as this."

The Treasury declined to comment.