Concern is mounting in the ranks of the fragile coalition about a shortfall in revenue and foot-dragging on a number of reforms as foreign inspectors prepare to return to Athens and union opposition to austerity peaks.

Prime Minister Antonis Samaras is due to discuss these and a host of other problems during a meeting scheduled for 6 p.m. on Monday with his coalition partners, socialist PASOK leader Evangelos Venizelos and Fotis Kouvelis of Democratic Left.

According to sources, serious delays in the implementation of reforms allocated to several ministries have prompted the premier to consider a government reshuffle, most likely next month following the scheduled congress of PASOK. Both Venizelos and Kouvelis are reportedly interested in increasing their parties’ involvement in the cabinet.

It remains unclear which ministers are likely to be dismissed though sources suggest that Samaras is unhappy with the performance of the Health, Administrative Reform, Environment and Justice ministries. Finance Minister Yannis Stournaras and Public Order Minister Nikos Dendias are believed to be the only two whose portfolios are “safe,” while Development Minister Costis Hatzidakis may be flanked by another official to boost efforts at drawing sorely needed investment.

Samaras was scheduled to meet with Hatzidakis over the weekend to discuss stalled plans for privatizing state assets – a rich potential source of much-needed revenue that remains largely unexploited due to fears of the political cost of projects that will incense unions as well as bureaucratic hurdles.

The country’s two main labor unions have upped the ante already, following weeks of rolling strikes by transport workers, calling a 24-hour walkout for Wednesday in protest at the government’s ongoing austerity drive.

Of greater immediate concern than the union pressure, however, are a series of worrying economic figures. The government will need to find ways of bolstering revenue, which last month was 7 percent below the budget target, while social security contributions are down by some 15 percent. With virtually no concrete progress on the levels of investment and privatization, it is expected that the troika will push the government to boost tax revenue and proceed with layoffs in the public sector.