Spain's Prime Minister has demanded that Catalan leader Carles Puigdemont should clarify whether independence has been declared.

Mariano Rajoy said the statement was needed from the pro-separatist leader before he can decide what to do next.

In a veiled threat, Spain's leader said clarity was required by the constitutional article declaring independence that would allow Spain to intervene and take control of some or all of Catalonia's regional powers.

He told a news conference Mr Puigdemont has sewn "deliberate confusion" and said he wanted to restore "certainty".

Mr Rajoy added: "This call - ahead of any of the measures that the government may adopt under Article 155 of our constitution - seeks to offer citizens the clarity and security that a question of such importance requires," Mr Rajoy said.

"There is an urgent need to put an end to the situation that Catalonia is going through - to return it to safety, tranquillity and calm and to do that as quickly as possible."

Mr Rajoy's demand followed special Cabinet meeting in Madrid to respond to Mr Puigdemont statement on Tuesday night that he would proceed the secession – but would suspend it for a few weeks to facilitate negotiations.

Together with other politicians from the Catalan parliament, he later that evening formally signed the document.

Deputy prime minister Soraya Saenz de Santamaria said the Catalan leader "doesn't know where he is, where he is going and with whom he wants to go".

She said Mr Puigdemont had put Catalonia "in the greatest level of uncertainty seen yet".

In a highly anticipated speech, Mr Puigdemont had said the landslide victory in the disputed referendum on October 1 gave his government in the regional capital, Barcelona, the grounds to implement its long-held desire to break century-old ties with Spain.

But he proposed that the regional parliament suspend the effects of the declaration to commence a dialogue and help reduce tension.

Madrid had said it did not accept the declaration and did not consider the referendum or its results to be valid in the aftermath of the Catalan leader's speech.

Speaking later yesterday in parliament, Mr Rajoy said Spain was facing the most serious threat to its 40-year-old democracy.

He said the pro-independence movement were behind an "anti-democratic plan foisting their will on all the people of Catalonia", and said the Spanish government had had no choice but to restore order.

"It falls to the Catalan leader to restore constitutional normality," he told deputies, rejecting any suggestion of outside mediation in the dispute.

Meanwhile, the country's two main parties have agreed to renegotiate laws governing autonomy amid Catalonia's independence bid, Madrid's opposition leader said.

However, Spain's socialist leader Pedro Sanchez, struck a more conciliatory tone.

Mr Sanchez said his party and the government were to look at the possibility of reforming the constitution.

It would look at "how Catalonia remains in Spain, and not how it leaves", he added.

He said a deal was reached with Mr Rajoy to open talks in six months on reforming the constitution that would allow changes to the current set-up governing Spain's 17 regions, including Catalonia.

Mr Sanchez said his party wanted the constitutional reform to "allow for Catalonia to remain a part of Spain".

Mr Sanchez said his party is backing Mr Rajoy, who leads the ruling Popular Party, in pursuing clarification from the Catalan regional leader over whether independence for the northeastern prosperous region was declared on Tuesday.

Mr Sanchez said Mr Puigdemont needs to put it in "black and white" what his plans are.

The referendum saw 90 per cent of voters back independence with a turnout of 43 per cent, according to the Catalans. But it was boycotted by voters opposed to Catalonia leaving Spain and there were also reports of irregularities in the voting procedure.