Campaigners are set to discover whether the coalition's much-disputed high speed rail consultation was illegal when a judge finally delivers his ruling later.
Lord Justice Ouseley will confirm whether the government's 2011 consultation was lawful this morning after court hearings in December last year.
If the government loses, its plans for HS2 could be put back by several years. This would significantly extend a painful political process which has seen endemic cases of nimbyism (not-in-my-back-yard) attitudes across the Y-shaped network.
"In December there were five very detailed cases put against HS2, which when all combined together show quite starkly that the government has rushed HS2 through," Stop HS2 campaign manager Joe Rukin said.
"Coalition leaders have shined a spotlight on HS2 and walked into it, wanting to be associated with the project, but come next week they could find that they have linked themselves to an illegal project which everyone will see is being based on nothing more than sentiment and spin."
Five weeks ago ministers unveiled plans for stage two of HS2, angering campaigners. Rail minister Simon Burns has dismissed the legal challenge, saying last month he does not expect a "major hiccup" either way.
But a defeat for the coalition would be a significant setback to the Department for Transport, posing serious questions about its basic levels of competence after last year's west coast mainline fiasco.
Officials were forced to abandon the competition for the franchise after making "fundamental errors", the Commons' public accounts committee (PAC) concluded last week.
The threat of a legal challenge from Richard Branson's Virgin, which was set to lose its franchise, eventually forced the DfT to accept it had not properly conducted the competition.
"The Department for Transport's complete lack of common sense in the way it ran the West Coast franchise competition has landed the taxpayer with a bill of £50 million at the very least", said Margaret Hodge, chair of the PAC.
Now the department's handling of the consultation on the £32 billion HS2 proposal, which will not be completed for at least 20 years, is under the spotlight.
Anti-HS2 lawyers argued the government failed to provide adequate information on the plans and did not sufficiently assess the impact on local communities or other parts of the transport infrastructure.
They claimed the government had "disenfranchised" those affected by the second phase of HS2, extending the network north of Birmingham in two branches extending to Manchester and Leeds.
Local people whose homes and businesses could be uprooted by the reform have by now adopted a resigned attitude to the process which is unlikely to change regardless of today's result.
"It's frustrating, the whole community is living in limbo land," parish councillor Isobel Darby of Chalfont told the Buckinghamshire Examiner earlier this month.
"We await the results of the judicial review with interest, but whatever way it goes there will probably be legal challenges either from the side of the communities and organisations who took the review or on behalf of HS2 if it doesn't go their way. It won't be the end, just a breathing point."