The "Together for Yes" coalition won 62 seats in regional elections on September 27th and has been courting the far-left secessionist CUP, which has 10 seats, to seal a majority in the 135-seat Catalan parliament.
The two parties approved a resolution last month which calls on the northeastern region's assembly to start working on legislation within 30 days to create a separate social security system and treasury, with a view to
completing independence in 18 months.
But the CUP has so far refused to back a return to power by Catalan president Artur Mas because of his austerity policies of recent years and his party's links to corruption scandals.
The Together for Yes proposal includes a promise to dedicate one percent of the Catalan budget - €270 million ($294 million) - on social spending such as school meals for poor children and aid to homeowners facing eviction.
But it refused to meet one of the CUP's main demands - that the next government be headed by someone else than Mas.
"It is not an agreement, it is a proposal of an agreement made by Together for Yes which the CUP must study within an assembly and approve if appropriate," said Together for Yes spokesman Raul Romeva.
The CUP, an anti-capitalist party that opposes NATO and EU membership, will meet Sunday to decide whether to form a coalition government with Together for Yes.
The party is steered by its base and places great emphasis on collective leadership, so the outcome of the assembly is uncertain.
The Catalan parliament has until January 9 to elect a leader and form a new government or it must call fresh elections, which would be a setback for the secession drive.
It would be the fourth round of elections since 2010 in Catalonia, which represents nearly a fifth of Spain's economic output.
The divisions among Catalonia's secessionist camp appear to have benefited new anti-austerity party Podemos, which came first in the region in Spain's general election on Sunday.
Podemos wants Catalonia to remain a part of Spain but is in favour of allowing an independence referendum in the region like the one held in Scotland in 2014, which resulted in a "No" vote.
All other national parties refuse to allow a referendum, judging it against the constitution.
With its own language and customs, Catalonia already enjoys a large degree of freedom from Spain in education, health and policing -- but wants more, particularly where tax is concerned.