Sweden will follow Denmark by introducing strict immigration controls, the leader of its populist opposition party has promised a week after launching a breakthrough deal with parties likely to take power next year. "Denmark was the same way as Sweden, and then it just changed overnight, and that will happen in Sweden too," Jimmie Åkesson said in a rare interview with international media. Last Sunday, the Sweden Democrats and the three centre-Right parties announced a proposal that for the first time showed them negotiating and setting migration policy together, something Mr Åkesson described as "a very important symbol" of cooperation. The move mirrors a deal made in Denmark that gave the Danish People's Party a stranglehold on the right-wing government and dramatically shifted political debate in the country, with even the current Left-wing government driving through a string of controversial migration policies this year including plans to send Syrian refugees home and plans to open a migration processing centre in Rwanda. "We actually in Sweden need a stricter policy than Denmark, because we have much bigger problems, Mr Åkesson told The Telegraph. "I don't think it's possible to just decrease immigration to Danish levels anymore. We need to take it further." Public opinion in Sweden has seen a marked shift since the refugee crisis in 2015, with 40 per cent of the population concerned about the "rising number of refugees" last year, according to an opinion survey by the SOM research institute, up from 22 per cent in 2011. Voters have rated immigration and integration as the most important social problem for four out of the last five years, according to the institute, with law and order, another Social Democrat campaign issue close behind.