Comyn said that even though customers were not technically in financial difficulty, there was no question large numbers of people were changing their spending patterns in response to rising costs.

CBA’s deputy chief executive, David Cohen, also pointed to the impact on younger customers, saying the biggest decline in spending had been among 25 to 29 year-olds, who may have been affected by rising rents.

Despite these pressures, Comyn said the number of customers failing to make their repayments was “low by historical standards”.

Meanwhile, Westpac chief executive Peter King also said conditions were getting harder for households, and the bank expected the cash rate would climb to 4.6 per cent. King said the bank’s stressed loans were at record lows, but unemployment – currently low at 3.6 per cent – was the key metric to watch.

“If we start to get a lot of people out of jobs, and the unemployment rate goes up, then there will be people that can’t pay their debts,” King said.

He added that the households’ high savings and the delay in interest rates being passed through had meant the “vast majority” of customers were in good shape, but added: “I don’t think it will stay like that for the rest of the year. At some point, it will turn.”

Comyn was also quizzed about the bank’s profitability, as part of an inquiry looking at competition, economic “dynamism” and business formation. He agreed the bank made big profits in absolute figures, but he said it needed to be seen in the context of the bank’s $1 trillion balance sheet, and “benign” economic conditions.

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“The measure of profitability for any industry is less about the size of the profit, it’s the return on the capital invested,” he said.

Comyn also pointed out CBA was one of the most widely held stocks in Australia, and said there was fierce competition in home loans, highlighting the boom in refinancing.

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