Western Isles ferry operators have released the controversial legal advice which forced it to begin Sunday sailings between Ullapool and Stornoway.
Ferry firm Caledonian MacBrayne (Cal Mac) decision in July to break the Sabbath angered many in the Presbyterian islands.
Campaigners against the Sunday service had publicly doubted whether the legal documents even existed.
The Sunday ferry has proved popular with islanders with more than 7,000 passengers and 2,000 cars using the in its first three months.
There were mixed scenes during the first Sunday voyage in July as supporters and opponents of the move turned out.
The Free Presbyterian Church later asked islanders to boycott the service.
Cal Mac sought legal advice after pro-ferry campaigners complained to the Equality Commission which in turn approached the company.
Though there was no threat of court action Cal Mac directors feared they could be prosecuted under the Companies Act as the legal advice said the company's ban was unlawful. The Scottish Government, which owns the ferry firm, also demands that Cal Mac operates within the law.
The firm published the legal advice documents following its board meeting this week.
A spokesman said: "We have never ruled out releasing it and have been regularly
reviewing the situation. We believe the time has now come when we should release it"
Cal Mac said: "In February 2009, several residents of Lewis and Harris approached the Equality and Human Rights Commission (EHRC) to say that CalMac's failure to provide Sunday sailings on the Stornoway and Ullapool service was in breach of the Equality Act 2006.
"In light of this challenge, Cal Mac sought an Opinion from Senior Counsel who agreed that Cal Mac was acting unlawfully."
A council spokesman said Cal Mac had asked its lawyer a loaded question, to get the answer it wanted and accused CalMac of inviting a legal challenge in order to start the Sunday service.
