Former Bank of England governor Mervyn King said Britain's finance ministry was in a difficult position after making exaggerated claims about the economic risks of leaving the European Union in the run-up to last week's referendum.

"I think the Treasury is in a difficult position now because it did make very clear forecasts which I think were exaggerated in terms of at least the certainty they led people to believe could be attached to those forecasts, and now I think they're going to have to row back," King told BBC television.

British finance minister George Osborne said earlier on Monday that he would not rush through a so-called emergency budget, despite having suggested during the campaign that he would have to do so after a vote to Leave the EU.

"We've already seen in the space of this morning that there will not be an emergency budget, and I think that that was perhaps the nadir of the exaggeration," King told the BBC.