The government has pledged to be a model payer and settle 80% of its invoices within five days days and the rest within 30 days.
But latest figures show those targets have been missed.
Latest data for the second quarter of the 2018/19 financial year shows 75.1% of invoices were paid within five days and 88.8% within 30 days.
The Cabinet Office is leading a crackdown on late payment in the private sector and its performance has sparked an outcry from the opposition.
Labour’s Shadow Minister for Cabinet Office, Jon Trickett MP, said: “The Cabinet Office has failed to get a grip on this important issue despite talking tough, and this is simply not good enough.
“Labour will overhaul procurement and ensure that government departments, and firms that receive public money to deliver goods or services, meet strict payment performance targets.”