LONDON — Sweden’s minority center-left government fell on Wednesday after Prime Minister Stefan Lofven failed to get his budget through Parliament. Mr. Lofven took office only two months ago. The far-right Sweden Democrats, now the third-largest party, sided with the opposition, defeating the budget by 182 votes to 153. Mr. Lofven said he would call new elections for March 22, adding that he would not work with the far-right party, which wants to restrict immigration. “I cannot let the Sweden Democrats dictate the conditions,” he said. Constitutionally, he must wait until Dec. 29 to call new elections.