Taxpayers' Alliance President Harl Heinz Däke called the increase ‘shameless' in an interview Wednesday in the German newspaper Saarbrücker Zeitung.
On the heels of a 9 percent raise in November, a two-tiered 6 percent raise would hike MP pay 16.4 percent, Däke said.
Dirk Niebel, secretary general of the liberal opposition party the Free Democrats (FDP), called for an independent commission to set MP pay.
“Public sector wage contracts do not necessarily have to be transferred to MPs and their paychecks,” Niebel told the newspaper Rhein-Neckar-Zeitung.
Leaders of the Christian Democrats (CDU) and their coalition partners the Social Democrats (SPD) proposed the increase to keep pace with public sector pay that is rising in the wake of labour struggles across Germany.
Under the pay increases now planned, the 612 members of Germany's Bundestag would see their monthly pay rise €278 ($430) to €7,946 on Jan. 1, an increase of 3.63 percent.
A second 2.68 percent raise – an increase of €213 each month to €8,159 – is planned a year later.
Representatives of trade union Verdi, which has led strikes and wage disputes, said they were astonished at the proposed increase and that MPs should not automatically benefit from increases fought for by civil servants.
“The MPs have to make their own case for why they think their pay should increase,” Klaus Weber, Verdi division head for the civil service, told the newspaper Berliner Zeitung.