Boris Johnson is expected to examine crucial hospital data on Monday before making any new announcement on Covid measures, but has no plans to recall his cabinet, with ministers still deeply sceptical of further legal curbs.

Sources said the prime minister would “take stock” after being encouraged by improving data on Friday, a sign that No 10 is leaning away from stricter curbs in England, but Downing Street sources said he would act quickly if there were new causes for concern.

Instead, Johnson will receive only his regular data briefing over the bank holiday with England’s chief medical officer, Prof Chris Whitty – expected to be knighted in the new year honours – and the chief scientific adviser, Sir Patrick Vallance.

Key evidence that the government will examine on Monday includes data on the length of stay in hospitals, the transition rates to ICU and new death figures. There is concern among some government figures about undeclared positive cases – including those asymptomatic but also those isolating after a lateral flow test whose results are not recorded by the NHS because they do not take a PCR.

However, cabinet ministers are still highly sceptical of further legal restrictions, a week after a tense three-hour cabinet meeting in which the majority pushed back against any new curbs.

One cabinet minister said the positive data on Omicron’s severity – a Health Security Agency analysis found those catching Omicron are 50% to 70% less likely to need hospital care compared with previous variants – proved they had been right to hold out.

“The data so far is still struggling to be persuasive of legal changes to be required,” one cabinet minister said. Another said it was “right that we didn’t rush last time given positive, early data”.

But a hospital doctors’ trade union urged ministers to implement further measures without delay to help the NHS, including limits on household mixing and table service only in hospitality venues.