The Turkish Parliament has voted in favour of opening a debate on a proposal from the governing AK Party to lift legal immunity from lawmakers.
During sessions on late Tuesday and Wednesday, 348 members voted in support of debating the bill proposed by the AK Party last month.
But the number fell short of the 367 required to make the constitutional amendment.
There will be a second round of voting on Friday.
In the first round 155 members voted against debating the bill, 25 did not take part in the voting and 22 members were absent from the session.
If the proposed law does not receive the required 367 votes then the president could ask for it to be put to a referendum. A referendum would need the support of 330 deputies to go ahead.
Some 136 deputies have had criminal proceedings lodged against them. There are 619 dossiers in total which could lead to legal processes being taken against MPs.
Lawmakers in the Turkish parliament are currently immune from prosecution while in office.
The chairman of the main opposition CHP, Kemal Kilicdaroglu, initially said his party would support the proposal but the result suggests it will vote in opposition to it.
Turkey’s governing AK Party currently has 316 deputies in the parliament and needs support from opposition parties to pass the bill. The HDP, whose members have the most dossiers against them, announced it would not support the bill.
The nationalist MHP has said it would vote in favour of the proposal.
The debate on lifting parliamentary immunities began after members of the HDP were accused of making statements supporting the PKK, which is designated as a terrorist group by Turkey, the US and EU.