HAMBURG, June 20 (Reuters) - IG Metall, Germany's most powerful union, wants to push through wage increases of between 7% and 8% in the upcoming round of bargaining for the 3.9 million employees in the metal and electrical industries, it said on Monday.

The demand, which has yet to be formalised following consultations with union branches on July 11, comes as inflation has soared across Europe on the back of a major rise in energy costs, driven up by Russia's invasion of Ukraine.

IG Metall justifies its recommendation, which was made by the union's executive board to the collective bargaining districts for negotiations with employers, by big profits of carmakers, including Mercedes-Benz and BMW.

The union said that the wage increase demand would not be able to offset the rapid rise in costs for power and gas, adding that this required a further scheme by the German government to ease the burden on households.

Though final wage deals tend to be far below initial union demands, the figure is still likely to worry European Central Bank policymakers, who fear that high inflation could get entrenched via rapid wage growth.

An oversized wage demand from one of the currency union’s largest unions will only raise fears that a hard-to-break wage-price spiral is already underway, even as the ECB has promised to tighten policy to fight back. (Reporting by Jan Schwartz, Illona Wissenbach and Balazs Koranyi; Writing by Miranda Murray and Christoph Steitz; Editing by David Evans)