By Belén Carreño and Joan Faus
Sanchez, in power since 2018, looks assured of winning a new term by a narrow margin in the 350-member assembly in exchange for the planned amnesty law for those prosecuted over Catalonia's attempts to secede from Spain since 2012.
The prospect of amnesty has brought thousands of opponents to the streets over the past week.
A draft of the bill - agreed after months of negotiations with Catalan separatist parties ERC and Junts and seen by Reuters - would exempt several crimes from the amnesty, such as terrorism or acts that have resulted in death.
Those who facilitated Catalonia's two independence votes in 2014 or 2017 will receive amnesty. Those who tried to prevent the ballots - such as police officers accused of using excessive force - are also protected by the proposed law.
According to local media estimates, it will benefit at least 409 defendants charged with various crimes over the years, of whom at least 73 are police officers.
Carles Puigdemont, the self-exiled pro-independence leader and a fugitive from Spanish justice for his role in the 2017 events, appears to be covered as the bill says that "the arrest warrants - domestic, European or international - for those persons to whom this amnesty applies shall be without effect".
He still faces an investigation related to organising a secretive protest group that could qualify as terrorism.
In an apparent concession by separatists following their illegal referendum in 2017, the text states that all political paths "need to transit within the national and international legal framework".
The European Union's foreign policy chief, Spaniard Josep Borrell, said on Monday the agreements with pro-Catalan independence parties gave him "some concern or quite a few concerns", without elaborating further. Borrell is a Socialist who served as Sanchez's foreign minister in 2018-19.
Spain's main business association said in a statement Sanchez's deals came during "an increasingly complicated business climate", could distort market unity and deteriorate Spain's image abroad.
After an inconclusive election on July 23, Sanchez's Socialist Party spent weeks negotiating support with smaller parties. Hard-left Sumar is set to become the junior partner in the coalition government.
His premiership bid is expected to garner 179 votes in favour and 171 against - mainly from the conservative People's Party and far-right Vox.
(Reporting by Inti Landauro, Belén Carreño, Joan Faus and David Latona; Editing by Andrew Cawthorne, Andrei Khalip and Josie Kao)
