The party claimed schemes currently running have just two weeks before their funding runs out and have not been told when applications for more cash will open.
Scottish Government funding has fallen in the last three years from £3 million in 2015/16 to £500,000 in 2017/18.
Labour MSP James Kelly called on the Scottish Government to announce the new funding of at least £1 million urgently.
Mr Kelly’s Member’s Bill to scrap a controversial law aimed at tackling sectarianism in football was passed at the Scottish Parliament last week.
He said: “Parliament has now recognised the importance of funding for projects to tackle sectarianism.
“The Football Act was scrapped because every opposition party knows that the roots of bigotry do not lie in football stands but in communities.
“Tackling sectarianism must start in schools by changing views and attitudes, and the money must be there for projects to do this effectively.
“The Scottish Government must listen to parliament, accept it has been defeated, and commit to re-investing in worthwhile anti-sectarianism schemes.
“SNP ministers can’t respond by putting their fingers in their ears. They have an opportunity to refresh their approach and listen to the experts and that starts by pledging the cash for these vital projects.
“Annabelle Ewing must now announce funding for anti-sectarianism projects as a matter of urgency, otherwise the government simply isn’t taking the issue seriously.”
Community Safety and Legal Affairs Minister Annabelle Ewing said: “There is no place for any kind of prejudice in Scotland and we are committed to tackling all forms of discrimination. This is why I made a commitment in the Scottish Parliament on March 15 to maintaining funding to deliver work to tackle sectarianism in 2018-19 and to providing a real terms increase to this.
“Since 2012, this Government has invested an unprecedented £13 million to support the delivery of anti-sectarian education in schools, prisons, workplaces and communities through community dialogue, workshops, peer-led programmes, intergenerational work and more.
“The repeal of the Offensive Behaviour at Football and Threatening Communications Act, without any attempt whatsoever to put an alternative in place, sends out an appalling signal which flies in the face of all of this positive work and will needlessly expose vulnerable communities to abuse.”