Voters line up to vote on Sunday Photograph: Yes Catalonia

Almost 2 million Catalan citizens have voted in an independence poll on Sunday, in defiance of Spain's constitutional court and the country's central government.

Two hours before the polls had closed, the regional government of Catalonia said 1.98 million citizens had voted in the independence poll, with the results expected on Monday evening.

Despite the state prosecutor ordering an investigation into any breaches of the court ruling, Catalan's regional police did not carry out any checks as some 41,000 volunteers staffed voting centres across the region. Schools and public buildings were used and advertisements ran in newspapers and on television in defiance of the court.

Voters were asked two questions, “do you want Catalonia to be a state?” and if so, “do you want that state to be independent?”. The vote saw all Catalans living abroad, from London to Hong Kong take part in the poll, as well as foreigners registered as residing in Catalonia.

Voters in Australia participate in the poll Photograph: Yes Catalonia

Catalonia's president Artur Mas cast his vote on Sunday and called for a formal referendum to be allowed which will allow Catalans “to be able to decide the future of our country in a legal and agreed manner.”

He called on the Spanish government to “listen to the clamour from Catalonia”, adding “this is not the definitive vote. But it is very important.”

Meanwhile Spain's prime minister Mariano Rajoy said that the poll would have “no effect whatsoever,” adding,

“Call it whatever you like, but it is not a referendum, not a consultation, nor anything that resembles it.”