"[ND's] obsession with the adoption of the entire Zappion II proposal does not help anyone and is only of concern to certain population groups," he said.
He stressed that ND's call for lower taxes "sounded good" but challenged the main opposition to say where the money would be found and not dwell only on the good news.
The spokesman pointed out that Greece had not yet secured the fifth tranche of the bailout loans and stressed that things were difficult, with negotiations with the EU-ECB-IMF troika at a "critical juncture".
At the same time, he dismissed the latest reports in the Financial Times as 'science fiction'.
On the issue of reaching consensus with the main opposition, Petalotis replied to ND leader Antonis Samaras that the government was not asking anyone for a "blank cheque".
"We are asking that all sides have an awareness of their responsibility so that the country can change. There is a common ground of understanding for taking the necessary steps and many things in common with ND," the spokesman added, noting that it was time to step beyond party boundaries.
Petalotis denied that a government reshuffle would be taking place over the next few days, pointing out that the government had a full work schedule in the near future with the passage of the Medium-Term Fiscal Strategy through Parliament, as well as the upcoming Eurogroup and EU summits in June.
He was also careful not to align himself with the opinions expressed by Foreign Minister Dimitris Droutsas concerning the political system and the role of MPs, noting that these were the minister's "personal opinions".