Although UK officials have decided against a fourth dose, the Telegraph understands that Boris Johnson and Naftali Bennett, his Israeli counterpart, exchange daily Whatsapp messages on how best to defeat omicron.

Sources close to the Israeli leader said the two men have been in constant, informal contact in recent months as they trade tactics on vaccines and avoiding lockdowns. At one point, Mr Bennett personally phoned Mr Johnson to walk him through the details of an Israeli study which found the fourth dose was both safe and effective.

“They’re speaking on a daily basis…I’d say it is a bromance, and bromance is beneficial to both countries,” an Israeli official told the Telegraph.

However, the exceedingly warm relationship with Mr Bennett, who has imposed some of the world’s toughest Covid travel restrictions, may rustle the feathers of hardline Tory MPs in the Covid Recovery Group.

Britain and Israel are also facing similar challenges on testing facilities. This week the Israeli government changed the rules so that the elderly and clinically vulnerable will take priority at overwhelmed PCR test centres. The fully vaccinated, meanwhile, will be offered rapid antigen testing kits at home.

Israel also this week eased its ultra-tough rules on international travel, which had forbidden Israelis from travelling abroad and stopped non-citizens from entering the country.

As of Friday, all countries have been removed from the so-called red list, which became redundant as the Omicron variant pushed the infection rate far beyond 15,000 cases per day.

Israeli health experts say the infection rate appears to be doubling every two days, but are reassured that the rate of deaths and hospitalisations is so far lower than in previous waves.