"We cannot confirm with certainty reports in some media that we have collected the enough number of signatures. We are close (to meeting the requirement), we cannot give you percentage," Ozren Matijasevic, who co-ordinates the five trade union federations, told a news conference in Zagreb on Tuesday.
The unions' signature-collecting drive was launched on June 9 and lasts until June 23.
By 23 June, they should collect signatures of exactly 449,506 Croatians over 18 years old with suffrage rights, or 10 percent of the entire electorate, in order to be able to launch the referendum procedure.
Yesterday, the unions reported that they had so far managed to secure 97 percent of required signatures.
Matijasevic today called on citizens to give their signatures in the last two remaining days before the expiry of the deadline, explaining that the campaign should ensure more signatures than required as the validity of every signature would be checked.
The unions announced another news conference on figures for Thursday morning.
Matijasevic thanked political parties which joined in the campaign.
He said the fact that the union's drive enjoyed the support of political parties ranging from right-wing to left-wing ones was the proof that the action was not politicised to the benefit of any of those parties but that this was an action of civil society for the common good.
The Croatian Labour Party leader, Dragutin Lesar, brought to the union federations boxes with lists of 80,006 signatures collected by his party's activists.
Describing the campaign as an action of solidarity Lesar said he expected that the referendum would be called.
Union leader Mladen Novosel said this campaign would put an end to attempts to systematically reduce workers' rights.