LONDON, Oct 12 (Reuters) - The delay to England"s first coronavirus lockdown was a serious error based on groupthink that went unchallenged, lawmakers said in a report published on Tuesday, adding that failures in testing positive cases and tracing their contacts exacerbated the crisis. 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. Deficiencies in the COVID-19 response in Britain have been laid out in a series of Reuters special reports, including about delays in the decision to lock down, shortcomings in the test and trace system and errors that led to the spread of the pandemic in care homes. The lawmaker report highlighted concerns about all three, adding there was a "policy approach of fatalism" that sought to manage but not suppress COVID-19 infections in the early stages of the pandemic, which it described as a "serious error". "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. Britain has reported 137,763 deaths within 28 days of a positive COVID-19 test result, the eighth highest coronavirus death toll in the world. The report said the rollout of COVID-19 vaccines was well planned and executed, but warned that overall, lessons would need to be learned to avoid repeating mistakes, and recommended more focus on pandemic contingency planning. "The UK’s response, with the notable exception of vaccine development and deployment, has for the most part been too reactive as opposed to anticipatory," the report said.