Catalonia's non-binding vote on whether or not to secede from Spain continues to cause acrimony and bickering at the highest levels of the European nation's government.
According to Reuters, the central government of Prime Minister Mariano Rajoy is planning to sue Catalan president Artur Mas i Gavarró for "disobedience and dishonesty" for ignoring a court order not to hold the election.
The wire service cited court sources who claimed that the complaint against Mas and his deputy, Joana Ortega, were being "fine tuned" and were likely to be filed on Wednesday or Thursday.
Catalan officials say 2.3 million people voted, with 80 percent of them approving secession. Rajoy has dismissed the result, pointing out that only about one-third of Catalans took part, despite months of pro-independence campaigning by Catalan authorities.
Some 6.3 million people were eligible to vote.
On Tuesday, Mas demanded that a permanent dialogue over Catalan independence and economic policy in the region, which includes the country's second-largest city, Barcelona, and accounts for about a fifth of Spain's population and economic output.
Angry at Spain's refusal to grant the region more autonomy, Catalan politicians have been pushing for an independence vote for two years.
Last week, Rajoy suggested that Madrid might be willing to grant Catalonia more say over tax collection and spending but he would never agree to a binding referendum on Catalan indepence.
The Associated Press contributed to this report.