In a two-day parliamentary debate on the state of the nation, brought forward by several weeks in response to the crisis, Mr Gonzalez will have to defend himself against allegations that he covered up anti-Eta death- squad activities in the Eighties, that his government is steeped in corruption and that his handling of the economy is inept.
The Prime Minister, who said last week during a visit to Belgium that he was going through "one of the worst political crises that I have had to face", is clearly feeling the strain. In recent public appearances his body has been stooped, his voice flat and his eyes dull.
Backed by 17 MPs from the Catalan nationalist Convergence and Union party, led by the wily old scrapper Jordi Pujol, Mr Gonzalez's Socialists are assured of a parliamentary majority. But in the country, opinion is turning to the conservative opposition Popular Party - nine or 10 points ahead of the Socialists in opinion polls - and it is widely expected that in May's local and regional elections the Socialists will be slaughtered, even in impoverished rural fiefdoms such as Extremadura.
The Popular Party's dearest wish is for early general elections. It is putting down about 30 motions for tomorrow's debate but the proposal to form an alternative government is not, so far, among them. Many observers see that as a sign of weakness and lack of confidence on the part of the party leader, Jose Maria Aznar, saying he, not Mr Gonzalez, has been the real loser in these weeks of crisis.
Instead of seizing the initiative, Mr Aznar has, critics say, messed about, totting up parliamentary votes and flirting incongruously with the far left, letting slip the opportunity to open up communication with the powerful nationalist leaders in the Basque country and Catalonia and failing to rally people at large in a crusade to sweep the Socialists from power.
All that might have been achieved by slapping down a censure motion which, even if lost, would have been a popular act of defiance.
The key figure in all this is Mr Pujol, who has pledged to support Mr Gonzalez at least until the end of the year in anticipation of important gains for his region on the back of an expected economic recovery. "If there is anything positive to be done inthis country at the moment, it must be done with the Socialist Party," Mr Pujol told journalists in Barcelona at the weekend.
The Socialists were, he said, the only party with which he could form a majority. Despite the political gulf between the two, his support for the Socialists' economic programme was "vigorous and solid", he insisted. But it was a high-risk strategy. "We are staking a lot," he admitted.
The biggest threat hanging over Mr Gonzalez remains that of Gal, the anti-Eta death- squads that killed more than 20 people. The man who was number two at the Interior Ministry throughout those years, the former secretary of state for security Rafael Vera, was last week questioned by the judge in the case, Baltasar Garzon.
The judge is thought likely to take Mr Vera into preventive detention in coming days in connection with an attempted cover-up of Gal operations.
Mr Vera is not expected to "grass" on his former ministers but, as Judge Garzon pads quietly and determinedly after him, the garrotte squeezes notch by notch around Mr Gonzalez.