Gareth Lee (pictured leaving court today) said he was left 'shocked' and in 'disbelief' when the bakery refused his order . A Christian baker who refused to make a cake bearing a pro-gay marriage slogan has begun a court battle over equality laws. Belfast-based Ashers Bakery refused to make a cake featuring an image of Sesame Street puppets Bert and Ernie below the motto 'Support Gay Marriage'. Northern Ireland's Equality Commission is now supporting a legal action against the family-run bakery on behalf of gay rights activist Gareth Lee, whose order was declined. Mr Lee told a court today he was left 'shocked' and in 'disbelief' when one of the owners of the bakery, Karen McArthur, rang him and told him she would not be processing the order he had already paid for. 'It made me feel I'm not worthy, a lesser person and to me that was wrong,' he said. Opening the case, Robin Allen QC, representing Mr Lee, said the baker's objection on religious grounds was not lawful. He said baking a cake did not mean the bakers supported any message the cake might carry and compared the baking of a cake to a postman delivering a letter or a printer printing a poster. 'A postman taking a letter to the door or a printer carrying out a printing job - nobody would say that involved promoting or support,' he said. 'It's simply a functional relationship, a working relationship.' The lawyer also noted the publicity around the case and highlighted that politicians, church figures, bloggers and others had expressed opinions on the matter. But the barrister insisted the case must be judged on the facts alone, saying: 'Law must not be determined by those who shout loudest.' Mr Allen QC said he was not in court to challenge the McArthur family's faith and highlighted that the proposed design would not have had an Ashers logo on it. The case is being heard at Belfast County Court by district judge Isobel Brownlie. The Commission, which monitors compliance with equality laws in the region, has alleged that the stance of the company was in breach of legislation. The case has sharply divided public opinion in Northern Ireland and beyond. In the wake of the bakery's refusal to provide the service last May, the commission, a state-funded watchdog body, took on the case on behalf of Mr Lee. Initially, the commission asked the bakery to acknowledge that it had breached legislation and offer 'modest' damages to the customer. Claims of discrimination were made after a Christian-run bakery in Northern Ireland refused to make a cake with a pro-gay marriage slogan on it on religious grounds. Pictured, left: The design. Pictured, right: Belfast Councillor Andrew Muir cutting the cake which was eventually made by another bakery . Ashers bakery general manager Daniel McArthur, supported by his wife Amy (right), has said he is fighting the case to allow Christian business owners to follow their beliefs in how they run their firms . When Ashers, which is owned by the McArthur family, refused, the commission proceeded with the legal action. Outlining his view of the facts, Mr Allen said Mr Lee had used the bakery in Royal Avenue in Belfast city centre 'regularly' before the incident. He said his client had seen a leaflet in the shop advertising a service whereby images could be printed in edible icing on a cake. He said there was nothing on the leaflet which suggested a limitation on the service due to 'religious scruples'. The barrister told the court that the order was accepted by Ashers director Karen McArthur and Mr Lee paid for it in full. 'A contract was therefore concluded,' he said. Mr Allen said that, over the next few days, Mrs McArthur expressed concern about the requested cake design with her daughter-in-law, Amy, and the matter was then discussed with her son, Daniel. After that Mr Lee was informed that his order would not be processed due to the family's religious views, said the lawyer. A court was told  that for the bakery to refuse to make the cake was like a postman refusing to deliver letters . Mr Allen said if companies were allowed to break contracts with individuals then 'the law is worth nothing'. He added: 'The rule of law says there shall be no discrimination in the commercial sphere.' The barrister insisted that Ashers was not an 'explicitly religious' business and referred to an interview Daniel McArthur gave to a newspaper in which he claimed the majority of his 60-plus workforce were unaware of his family's faith. Mr Allen stressed the importance of anti-discrimination legislation in Northern Ireland, given its history of sectarian strife. Daniel and Amy McArthur sat on one side of an almost packed courtroom, with Mr Lee watching from the other side. The Ashers case has prompted the Democratic Unionist Party to propose a law change at Stormont that would provide an 'equality clause' which would essentially enable businesses to refuse to provide certain services on religious grounds. Mr McArthur has previously said: Mr McArthur has previously insisting that Christians should be able to apply their beliefs to the day-to-day running of their businesses. He said: 'I would like the outcome of this to be that any Christians running a business could be allowed to follow their Christian beliefs and principles in the day-to-day running of the business and that they are allowed to make decisions based on that.' The hearing continues. Mr McArthur, with his wife Amy and daughter Robyn, sat in court today to hear the legal argument .
Bakery owned by Christian family refused to make gay marriage cake . They have been accused of discrimination by gay rights campaigners . Court case starts examining whether bakery discriminated over the issue . Lawyer for equality campaigners says religious refusal was unlawful .