* Both sides say still open to dialogue
* Catalan parties stick to red line on referendum
* Budget approval hinges on Catalan parties
* Opposition calls for protests, snap election over policy (Adds quotes by PM, deputy PM, Catalonian officials)
By Belén Carreño and Jose Elías Rodríguez
MADRID, Feb 8 (Reuters) - The Spanish government accused Catalan pro-independence leaders on Friday of rejecting its attempts to start a dialogue aimed at resolving the separatist crisis between Madrid and the wealthy region.
The impasse comes at an uneasy time for Prime Minister Pedro Sanchez's minority government ahead of a vote next week on the 2019 budget bill, which is likely to fail without the support of the Catalan parties, and of the trial of 12 jailed independence leaders starting on Tuesday.
Deputy Prime Minister Carmen Calvo said the pro-independence groups had rejected the framework for talks proposed by the government because they wanted a referendum on independence included on the agenda, which Madrid would not accept.
"For years they have been asking for dialogue. We have done it. If that is not enough, we need to stop," she told a news conference after the weekly cabinet meeting.
Failure to approve the 2019 budget proposal could prompt a snap parliamentary election this year, which is something the opposition has also called for as part of its sharp criticism of the government's plan to open talks with Catalan secessionists.
The government's proposed framework included bilateral meetings between the central and regional administrations as well as a cross-party coordinator. The conservative opposition has accused Sanchez's Socialist government of giving ground to the secessionists and preparing what they called a treasonous deal.
Sanchez, who came to power in June last year and has been open to giving Catalonia a greater autonomy, said in a tweet the government's proposal for dialogue remained open and his administration was working to "build all possible bridges".
But he reiterated that Madrid will never accept a referendum on Catalonia's independence.
In 2017, Catalonia proclaimed independence after a referendum, deemed illegal by Madrid, leading the previous conservative central government to seize control of the autonomous region.
Catalonian Vice President Pere Aragones from the pro-independence ERC party blamed the failure to advance on the Sanchez government, which he said had ceded to pressure from the Spanish right and far-right in refusing to even discuss independence.
Catalonia remained open to dialogue, but it "cannot be expected to renounce the right to self-determination", Aragones said.
Catalonian government spokeswoman Elsa Artadi said that maintaining a dialogue was the necessary condition for the approval of the budget, and Madrid walking out of it would mean that "the likelihood of the budget approval is more distant".
The centre-right People's Party, Ciudadanos and far-right Vox have called on supporters to take to the streets of Madrid on Sunday draped in Spanish flags to protest against the government's stance on Catalonia. (Writing by Andrei Khalip Editing by Frances Kerry)
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