If Madrid decides that Catalonia is acting unconstitutionally, Rajoy has the option of imposing direct rule on Catalonia under Article 155 of the Spanish constitution, drawn up after the Franco military dictatorship was toppled in 1975.
"I have to represent all of Catalonia's citizens", said Puigdemont, who also repeated his calls for dialogue with Madrid.
We have received various offers in the last hours and we will receive more.
Together with other entities of civil society, we want to help build bridges of dialogue that contribute to solving this conflict in a consensual and peaceful way.
"Our institutions are going to apply the results of the referendum in the coming days", has he hammered. "I can assure you that we will defend the sovereignty of the Parliament and the freedom of speech, as well as the lawmakers' right of initiative".
On Thursday, Spain's Constitutional Court ordered the suspension of the session which was scheduled to begin on Monday.
"Is there a solution?"
Spanish five-year credit default swaps - which measure the risk of a default by the Spanish government - hit their highest since March and the Standard & Poor's credit rating agency has said it may downgrade Catalonia's debt rating, although the region has only some €5.36 billion of Euro-denominated bonds outstanding. "And the best one would be a return to legality and the swiftest possible confirmation that there won't be a unilateral independence declaration, because that way still greater harm could be avoided".
The conflict over a self-determination vote has been dragging on for six years but Catalan separatists staged an independence referendum on October 1 despite Spain's insistence it was illegal.
"The 155 needs wide-ranging backing because we don't know whether it will resolve problems, and if it's only backed by one party in congress then it will be hard to obtain the backing of a majority of Catalans", said Rafael Hernando, who serves as a parliamentary organizer for the PP.
Madrid has branded the vote a "farce" and Spain's King Felipe VI sided squarely with the central government on Tuesday, accusing separatist leaders of "disloyalty".
Prime Minister Mariano Rajoy's office retorted in a statement: "The government will not negotiate over anything illegal and will not accept blackmail".
His criticism of the king showed that he was "out of touch with reality", it added.
He told German newspaper Bild: "I already feel as president of a free country where millions of people have made an important decision".
Catalan authorities claimed some 2.3 million people - less than half the region's electorate - voted in the referendum Sunday.
Catalans who favor remaining part of Spain mainly boycotted the ballot and many polling stations were closed.
Spain's government has passed a law making it easier for companies to move their official base out of Catalonia, a move that could deal a heavy blow to the region's finances.