The right of Ukrainians to live and work in the European Union following the Russian invasion may need to be extended for 10 years, special adviser Lodewijk Asscher has said.

The former Dutch Labour party (PvdA) leader was appointed last year to advise the European Commission on arrangements for Ukrainian refugees.

In a report published on Tuesday he described the decision to grant them special status as “the most important decision the European Council has taken”.

Since March last year Ukrainians have been allowed to move to the 27 EU countries and start work immediately without waiting for a permit or settled asylum status.

Asscher said the EU should extend the temporary protection scheme, which is separate from its regular asylum procedures, for as long as necessary.

“The Russian invasion of Ukraine has been a huge challenge for Europe: international principles and European values such as sovereignty, democracy and the rule of law are on the line,” he wrote.

“As the war enters its second year, the outcome will determine our future.”

Some four million Ukrainians are benefiting from temporary protection, including 112,000 in the Netherlands. Germany is home to more than a million Ukrainian refugees, closely followed by Poland.

Ukrainians who fled the country since last February have the same rights to housing, healthcare and welfare as EU residents, and can move to another member state without waiting for a residency permit.

Asscher also warned of the risk of “solidarity fatigue” if the war drags on for several years and called on the EU to support member states with housing and welfare for Ukrainians, “to avoid the risk of tensions between government and society or the perception of double standards”.