He was challenged on the topic during a Mayor’s Question Time session by Peter Fortune, the Conservative London Assembly Member (AM) for Bexley and Bromley.
At the public meeting on Thursday, Mr Fortune told Mr Khan that according to City Hall’s own figures, the organisation has failed to hit its target of making 90 per cent of payments on time, every year since he took office as Mayor.
The figures provided to Mr Fortune stretched back over the last decade, showing that in Boris Johnson’s last three years as Mayor, the target was hit each time.
The Tory AM said that the 2021-22 figure of 79 per cent of payments being made on time meant that some £16.5 million was delayed from reaching small and medium firms (SMEs) that year.
In 2022-23, just 74 per cent of payments were made on time - the lowest since the figures provided began.
Mr Fortune reminded the Mayor of previous occasions when he had raised the issue with him, when Mr Khan had said he recognised how important cash-flow was for small businesses, particularly those struggling after the pandemic.
Mr Fortune said on Thursday: “I asked this question in September 2021, I asked it again in June 2022, here we are in 2023.
“You’ve promised to grip this, you’ve promised to take control of it. Why are things getting worse?”
Mr Khan replied: “It’s simply not good enough. Even if you excuse the Covid years, what your stats show is it’s poor before the Covid years and it’s poor after the Covid years, so that’s not a good enough reason.”
The Mayor reiterated that “the cashflow coming in is the difference between [small businesses] paying bills and not paying bills”, which was a source of “heartbreak” for him.
He added: “To all those firms who have received payments later than they should have done, I apologise. As soon as Mayor’s Question Time is over, I’m going to look into this personally.”
Mr Khan offered to meet with Mr Fortune next week to discuss his findings and proposed actions to improve the situation.
The issue has been previously raised by the Federation of Small Businesses (FSB), who warn that companies are already struggling to make ends meet in the current economic climate.
Laura Timm, the FSB’s London policy chair, said: “Small firms are already being stretched beyond their limits with rising energy bills, rampant inflation, and a mounting cost of living crisis.
“It is therefore disappointing to hear that a quarter of small firms are being paid late by the GLA.
“The GLA and its other anchor institutions should be beacons of best practice in this area.
“Cash flow is already tight, and that is compounded by being kept waiting months for invoices to be paid, which is a serious roadblock to growth and investment…
“Poor payment practice should be a thing of the past and we need to make London a ‘Prompt Payment Zone’”.