Mortgage repayments could rise faster than expected, with Westpac chief economist Bill Evans tipping a double rate rise in June, taking the Reserve Bank’s official cash rate to 0.5 per cent in just seven weeks.

Financial markets are pricing in a 90 per cent chance of a 40 basis point lift in June, and are tipping the cash rate to reach 2.3 per cent by December, which would represent nine increases in the next eight months.