Nationalist leaders in the rich region in northeastern Spain have called a snap regional vote for September 27th centred on independence after Spanish authorities blocked their bid for a referendum on the issue in the courts.
Catalan president Artur Mas went ahead with a symbolic vote on independence last November organised by volunteers. The outcome, however, was mixed -- about 80 percent of the 2.3 million people who voted backed secession, but the turnout was little more than 40 percent.
His government is building the structure of an independent state in areas such as diplomacy, taxes and social security to be ready in case the pro-independence camp wins September's elections.
It has enlisted a former Spanish tax inspector, Joan Iglesias, to prepare the Catalan government to collect its own taxes.
The Catalan tax authority currently collects about five percent of the total amount of taxes raised in the region, which has a population of 7.5 million people and accounts for one-fifth of Spain's economic output.
Catalonia could collect around €100 billion ($113 billion) in taxes each year, much more than the €65 billion that an independent Catalan state would need, he added.
"Everyone knows that Catalonia would be viable economically," Iglesias told AFP, rejecting critics who argue an independent Catalan state would have a hard time financing itself and could not ask for European Union aid.
"It is the most economically productive territory in Spain," he added.
Disagreements over tax income are a key source of tension between Catalonia and Madrid.
The Catalan officials complain that the central government collects far more in taxes in the region than it spends in public sector expenditure.
It puts the difference at around 15 billion euros per year. The central government says the figure is much lower.
An independent Catalonia would also need to set up its own central bank, hire more civil servants and improve computer systems -- a gargantuan task.
"Work is advancing too slowly, we need to streamline our efforts so we arrive at the elections in September at a much more advanced state," said Lluis Salvador, a lawmaker in Catalonia's regional parliament with the separatist Esquerra Republicana de Catalunya (ERC) party.
Mas set up a commission in February that is charged with supervising the creation of the structures needed by an independent state.
The Catalan government's draft budget for 2015 increases the spending on the treasury department to 54.4 million euros from 35 million euros last year, which would allow it to boost hiring by 50 percent.
Mas has also ordered a study to determine what steps Catalonia needs to take to ensure that services such as telecommunications, energy distribution and transport that currently depend on the central government would continue to run smoothly after independence.
Catalonia recently opened two more offices representing its interests abroad in Austria and Italy and plans to open up to three more this year.
The region already has seven foreign missions, including in Britain, France, Germany and the United States.
The Catalan body charged with ensuring the constitutionality of Catalan laws, the Council for Statutory Guarantees, warned Thursday that the regional government did not have the authority to adopt some of the measures, in line with Madrid's argument.
"We feel that is it completely out of place that the creation of a parallel state is being promoted," Jose Antonio Coto, a lawmaker with Spain's ruling conservative Popular Party in the regional Catalan parliament told AFP.
"The government will take whatever steps are needed to prevent the waste of money," he added.
The September elections are a gamble for Catalonia's pro-independence camp.
Like the Popular Party and the main opposition Socialists, Catalan parties face a stiff challenge from new anti-establishment party Podemos, which is gaining strong support across Spain and opposes Catalan independence.
Polls show Mas' Convergencia i Unio (CiU) alliance and the second party in the region, the pro-secession ERC, falling short of getting 50 percent of votes between them.