The delay to England's first coronavirus lockdown was a serious error based on groupthink that went unchallenged, lawmakers have said in a published report, adding that failures in testing positive cases and tracing their contacts exacerbated the crisis.

The British parliament's health and science committees have jointly published a 150-page report on lessons learnt from the Covid-19 pandemic after hours of testimony from more than 50 witnesses, include government policy, health and science advisers.

"Our test and trace programme took too long to become effective. The Government took seriously scientific advice but there should have been more challenge from all to the early UK consensus that delayed a more comprehensive lockdown," lawmakers Jeremy Hunt and Greg Clark, who led the committees behind the report, said.

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