FRANKFURT (Reuters) - A record inflow of refugees to Germany should not be used as an excuse for driving down wages, the head of the powerful trade union IG Metall said on Sunday.
Detlef Wetzel said there had already been a push by employers to pay migrants with low qualifications less than the rates set out in collective wage agreements.
"There is no scope here to manage downwards. Everyone has the right to the minimum wage or the collective wage agreement," Wetzel said in an opening address to the four-yearly congress of Germany's biggest trade union.
Earlier this year, IG Metall secured a 3.4 percent wage increase for 15 months from April plus a one-off payment of 150 euros (110 pounds) - its biggest wage increase for years.
Concerns about the ability of the government to handle up to a million refugees who are expected to arrive this year have pushed support for Chancellor Angela Merkel's conservatives to its lowest since May 2013, a poll showed on Sunday.
Merkel is due to address the union congress on Wednesday.
Wetzel, a 62-year-old moderate, will step down on Tuesday. His deputy, 59-year-old economist and veteran wage negotiator Joerg Hofmann, is expected to be elected to take his place.
Wetzel has nominated board member Christiane Benner, 47, to be Hofmann's chief deputy, which would make her the first woman to rise near the top of a major German union.