There was a 61% increase in positive Covid-19 cases in England's latest weekly data, with more than four times the number of cases recorded as there were at the end of August, the health service's test and trace scheme said on Thursday.

Prime Minister Boris Johnson has implored Britons to follow tighter rules that have been introduced in a bid to stem a resurgence in Covid-19 cases and avert a crippling second wave that could overwhelm the health service.

The latest figures from NHS Test and Trace provide more evidence of a rise in cases.

"31,373 people tested positive for coronavirus (Covid-19) for the first time in England between 17 September and 23 September, a 61% increase compared to the previous week," it said in its weekly report.

"Positive cases have been rising steeply over the last four weeks with over four times as many positive cases identified in the most recent week compared to the end of August."

Test and Trace has been cited as a key element of combatting a second wave of the coronavirus, and Johnson has promised a "world-beating" system. However, latest statistics showed it had fallen short of reached a target of 80% of contacts once again.

Of the 29,047 people transferred to the system in the week, 71.3% were reached. Of their contacts, the system reached 71.6% of the 87,587 people identified as close contacts of a positive case.