LONDON — Britain will have the highest inflation of any leading economy in 2023, according to forecasts from the Organisation for Economic Co-operation and Development (OECD) which show Prime Minister Rishi Sunak will miss his promise to halve price growth this year.

Britain’s headline inflation rate was set to be 6.9% in 2023, higher than Germany’s 6.3% and France’s 6.1% and the OECD average of 6.6%, the group said in a new set of projections on its members’ economies published on Wednesday.

If correct, the forecast would mean Mr. Sunak will miss his target of halving inflation this year, one of the priorities he set out for voters before a national election expected in 2024. However, the OECD said it expected British inflation to slow to 2.8% in 2024, lower than in France and Germany.

Britain’s stubbornly high inflation rate has intensified expectations that the Bank of England will continue to increase borrowing costs, potentially pushing the economy into a recession which it has so far dodged.

Finance Minister Jeremy Hunt pointed to improved forecasts from the OECD for the economy which it now expected to grow by 0.3% in 2023 and 1.0% in 2024.

Previously the OECD had expected the economy to shrink by 0.2% this year and grow by 0.9% next year. — Reuters