Rubalcaba on Monday announced plans for the reactivation of Spain's economy including financial assistance for families and businesses.
Speaking in a press conference, the socialist leader also proposed the creation of a jobs strategy and solutions to fight the problem of home evictions in the crisis-hit country.
The PSOE plan would comprise two main pillars, according to Spain's El Pais newspaper.
The first of these measures would involve firms not being able to fire anyone on economic grounds for the next two years with the state subsidizing salaries if those businesses could not cover the total costs of employing staff.
The second part of the socialists' plan, meanwhile, would involve using €30 billion of European rescue money to recapitalize Spain's banks so that this money could be used to provide credit to families and businesses.
However, Brussels quickly responded by saying that rescue money provided by the group known as the Eureopan Stability Mechanism (ESM) was intended solely for the "cleaning up" of Spain's ailing banking sector.
Under the conditions of the ESM, the use of such rescue funds is only negotiable if loan conditions are redrawn.
The reaction from Rubalcaba — who, according to El Pais newspaper, appeared visibly troubled — was to state: "We are asking that Brussels listen and read what we are proposing.
"This is time for humility: in Moncloa (the head office of the government of the ruling Spanish Popular Party) and in Ferraz (the headquarters of the PSOE) and in Brussels".
The socialist leader added this was not the time for Brussels to "respond without thinking".
He went on to say that the attitude from the European Union should be like someone "giving lessons" and that Brussels should look at Spain's macroeconomic situation and ask whether they had played a role in the dire situation Spain found itself in.
On the other side of the political fence, Spanish Prime Minister Mariano Rajoy spent Monday defending the higher taxes imposed by the ruling Popular Party (PP).
"We didn't want to raise taxes," stated Rajoy during a meeting with the National Executive Committee of the PP. "But last year Spain was about to "crack" and it was necessary to carry out the policies we did to raise income."
The Spanish Prime leader went on to guarantee that taxes would come down as soon as possible and that 2015 was the target for this.
In response, the influential president of the PP for Madrid Esperanza Aguirre said Rajoy should have explained his new economic plans earlier.
She told news agency EFE that Monday's meeting had been very useful. The controversial party figure stressed, however, that Rajoy should have made clear on April 26th what his plans were.
In her opinion, the revised economic targets announced on that day had "disheartened the Spanish people".
On April 26th The government said Spain's economy would contract by 1.3 percent in 2013 before seeing growth of 0.5 percent in 2014.
But the PP also admitted it would probably take until 2016 to bring the country's public deficit under the European Union's three-percent limit.
Unemployment would slide to 26.7 percent over 2014 and ease back further to 25 percent in 2015, the government added.