This complies with a manifesto commitment of the party that leads the current governing coalition, SYRIZA.
The cynical interpretation, of course, is that they must not be very confident of remaining the largest party. Indeed, polling shows New Democracy (the prior ruling party, of the center-right) ahead. By a lot, though only around 30%, with SYRIZA in something of a free fall.
Nonetheless, the removal of the bonus adjustment will not take place in time for the next election, but rather would start with the one after that. Greece is one of the few (only?) democracies to mandate that an electoral system change can take effect immediately only if it obtains a super-majority.
As things stand, apart from the 144 SYRIZA and nine Independent Greeks lawmakers, the only other members of the House that intend to vote for the draft legislation are 15 from the Communist Party and nine from the Centrists’ Union, as well as two independent deputies. (Ekathimerini)
This left the law short of the required two thirds.
Of course, if the next government is made up of a party or coalition that likes the bonus, the reform law could be repealed. Hence the “maybe” in the title of this post.
(A later WSJ report–behind a pay wall–confirms that the bill passed, with well under 2/3.)