Greek Olympic preparations were in crisis on Wednesday after revelations the main stadium would not be ready until less than a month before the Games start and disintegration of political party unit supporting the event.

With a storm also gathering about calling in NATO forces to protect the Games from possible attacks, celebration of the modern homecoming of the Olympics in August after more than a century was increasingly pushed into the background.

The trigger for the crisis -- a week before the lighting of the Olympic flame at the ancient home of the Olympics in Olympia on March 25 -- was the election of a conservative government 10 days ago which ended a decade of socialist rule and exposed long suspected delays in preparations.

Al Qaeda links to train bombings in Madrid also added strains to International Olympic Committee (IOC) demands for "tough decisions" in the next two weeks to ensure the Games went ahead at standards the world had come to expect.

Greece has budgeted nearly one billion dollars, three times the amount spent on the 2000 Sydney Games, to protect the Athens Olympics but some Greek newspaper questioned whether inviting NATO to help would make it a bigger target.

"This decision upgrades the country's security arrangements against international terrorism but it also turns Greece into an attractive first-rate target for al Qaeda," the Ta Nea newspaper said this week.

FALLING BEHIND

In a sign of how far behind Greece has fallen, the builder of the main stadium said the venue would not be ready until July 20 -- three weeks before the August 13 opening ceremony.

Train and tram projects to help ease notorious traffic congestion in Athens have also come under fire from conservatives.

Transport Minister Michalis Liapis has ordered work around the clock to make up for lost time.

"At today's pace, there is not enough time to finish the project for the Olympics," Liapis said.

In what was an end of an all-party Olympic truce on staging the Games, former Culture Minister Evangelos Venizelos told reporters conservatives were exaggerating problems over preparations for the Games at the expense of Greece's international credibility and its key tourism industry.

Venizelos' words carried weight because socialists are closely linked to union members like construction workers who ultimately hold the fate of the Games in their hands by not joining strikes that could delay building work.

The delay in work on the main stadium until July 20 has major knock-on effects for security and the staging of opening and closing ceremonies which take weeks of rehearsal.

It also means a June athletics test event at the stadium will take place while work is still in progress.

"It (Olympic stadium) will be finished, along with the overlays, by July 20," Dimitris Kalitzatzis, managing director of constructor Aktor, told reporters.

The biggest concern is a 150-million-euro glass dome over the stadium that the IOC does not believe is even necessary but Athens organisers regard as the event's landmark building.

A less flamboyant, but equally needed, roof over the swimming pool to protect competitors from Greece's searing temperatures in August is also behind schedule.