Plans for the Spain's powerful northeastern region of Catalonia to hold a secession referendum Nov. 9 look uncertain as a pro-vote party says regional leader Artur Mas has told them the poll cannot go ahead as planned.

Joan Herrera, head of the leftist party ICV, said Mas told leaders of pro-vote parties at a meeting that ended late Monday that the referendum plan would have to have to be changed.

Mas is to hold a press conference Tuesday morning at which he is expected to confirm that that the vote will not go ahead as planned and to announce alternative plans.

The Spanish gov't has challenged the vote before Spain's Constitutional Court, which suspended its staging while it deliberates on the issue.