A severe wave of Omicron infections could threaten critical services such as the police and fire brigades, German Chancellor Olaf Scholz has said, as Europe braces itself for a second Christmas under the cloud of coronavirus restrictions. Germany and Britain are among the countries considering emergency measures as travel curbs return across Europe, hospital admissions rise and governments race to hand out booster vaccines to contain the fast-spreading Omicron variant. But European governments face protests and public fatigue as the spread of Omicron prolongs the uncertainty that has put people's lives on hold for almost two years. Demonstrations sprang up in Europe as restrictions loomed, with 13 people arrested after a march in Belgium led to scuffles and stones being thrown at police. In Germany, the two leaders of the far-right Alternative for Germany (AfD) party addressed a rally in Nuremberg protesting against vaccine mandates. Others held rallies in France and Italy. Germany's scientific advisers recommended curbing social contacts, but warned ministers that any such measures would face a battle for public support. “The Omicron wave is hitting a population that is exhausted by the pandemic and the fight against it, and tensions are visible every day,” an advisory panel said. “As well as decisive action, compelling explanations will be required.” Mr Scholz tried out one such explanation on Monday by highlighting the potential pressure on critical services, besides the healthcare system, if many people are forced to isolate. Britain <a href="https://www.thenationalnews.com/world/uk-news/2021/08/02/uk-to-tweak-covid-19-phone-app-after-pingdemic-disruption/" target="_blank">suffered weeks of chaos during the summer</a> when a contact-tracing app forced many people to isolate. “We will have to take care of critical infrastructure, so that if we have high infection rates, we can deal with the effects on particular services … whether it's the police, the fire brigade, hospitals, electrical supply or other things,” he said at a press conference with Italian Prime Minister Mario Draghi. “As well as the wide-reaching contact reductions that we have already implemented … we will bring other areas into play. A new set of rules to be agreed between Mr Scholz and state leaders on Tuesday would affect the social contacts of vaccinated people, he said. Currently, only unvaccinated people are subject to limits. “We have crossed a critical number of Omicron infections, and this wave can no longer be stopped completely,” said German Health Minister Karl Lauterbach. Although three vaccine doses are believed to greatly reduce serious illness, those calling for restrictions argue that even a small proportion of severe cases could put pressure on Europe’s hospitals. The Omicron variant <a href="https://www.thenationalnews.com/world/uk-news/2021/12/18/uk-mulls-new-covid-measures-as-omicron-runs-rampant/" target="_blank">is dominant in the UK</a> and Ireland, and infections are thought to be doubling every few days in Denmark, Norway and the Netherlands in the countdown to Christmas. Christmas markets are clouded by health restrictions in Austria, and banned altogether in parts of Germany, while moves to limit travel have put the winter holiday season in question. In Vienna, thousands of people lit candles stretching around the capital’s ring road on Sunday to commemorate those who have died from Covid-19 in Austria. Austria’s unvaccinated people will get a Christmas respite from <a href="https://www.thenationalnews.com/coronavirus/2021/11/14/austria-declares-lockdown-for-covid-unvaccinated/" target="_blank">a lockdown that has applied to them since last month</a>, but it will then be extended until January 10. The Netherlands <a href="https://www.thenationalnews.com/travel/covid-19-travel/2021/12/18/europes-omicron-travel-restrictions-countries-react-as-new-covid-19-variant-spreads/" target="_blank">made its move on Sunday</a> by returning to a strict lockdown over Christmas, with social visits limited and schools and non-essential businesses closed. Poland has moved schools to remote learning until January 9, and tightened capacity limits in restaurants and hotels. Ireland is closing restaurants at 8pm, while Denmark is shutting cinemas and other venues. In France, unions were called in for talks on making health passes compulsory in the workplace, as well as for restaurants and cultural venues. From January, negative tests will no longer qualify people for a pass, meaning only those who are vaccinated or recovered will be eligible. France has more than 15,000 patients in hospital, the most for six months. In Italy, average daily deaths are above 100 for the first time since June. Britain has seen days of record-shattering infection numbers but the ruling Conservatives are divided over whether to tighten restrictions. Advisers issued a warning that delaying measures until after Christmas would limit their effectiveness in slowing the spread of Omicron. But 100 Conservative MPs <a href="https://www.thenationalnews.com/coronavirus/2021/12/14/uks-boris-johnson-suffers-largest-rebellion-of-his-leadership-over-covid-passes/" target="_blank">rebelled against lighter measures</a> only last week, and Prime Minister Boris Johnson is at a political low point after a series of scandals. Ministers hope that the UK’s booster programme, one of the fastest in Europe, will prevent a return to severe restrictions. More than half the adult population has received a top-up dose.