A woman who lost her discrimination claim against Merton Council after refusing to work on a Sunday has said she was “amazed” at the decision.

This morning, Celestina Mba, of Mitcham, heard a tribunal rule that her employer did not unlawfully discriminate against her by asking her to work on Sundays at the Brightwell children's centre in Morden.

Miss Mba said: "I am amazed by this decision. I thought that this country was a Christian country and known for its welcome and hospitality to all people. I worked hard for years at my job, and to lose it because of intolerance towards my faith is shocking to me.”

Miss Mba, who was born in Sierra Leone and moved to Britain when she was 21, said she had loved her job, but did not make the claim against the council to win it back.

She added: “But I have my faith and so no one can put me down. God is here whether I win or lose and I would not choose anything above God - and this is what happened with my job."

The 57-year-old, who left her job as a residential care officer at the home, which provides respite for children with disabilities in June 2010, added her religious commitments on Sunday were wider than simply attending church service.

She said: “The activities I do on Sunday including teaching in the church, visiting people in hospitals and prisons is a part of worship. For me, Sunday is about worshipping God, and empowering and encouraging others. It is not just about attending a service.”

Andrea Williams, director of the Christian Legal Centre which supported Ms Mba in her claim, said the question of what constitutes core beliefs in Christianity was difficult.

"This is one of the great anomalies as in Christianity nothing is mandated."

She said the Centre was "extremely disappointed" by the decision and would consider appealing.

Ms Williams said: "Celestina was let down by her employers, who failed to continue to accommodate her beliefs. She was an employee who wished to observe Sunday. Her employers forced her to choose between her job and her faith. This was unacceptable, and we are disappointed that the Judge did not agree with her.

“There needs to be a reasonable accommodation of the Christian faith across the public sphere, for the good of all. Pressure from employers against Christians expressing their faith is an increasingly a regular hallmark of what Baroness Warsi has described as our 'deeply intolerant culture'.

"In less than 20 years we have moved to a situation in this country where Sunday is hardly observed at all and, if you do, you find yourself pushed out."

Earlier, at the London South Employment Tribunal, Judge Heather Willams QC said Merton Council did not promise Miss Mba that she would never have to work on Sundays when she interviewed for the job in 2007, but still reasonably accommodated her belief for two years - a belief which is not held by all Christians.

Judge Williams said Miss Mba's former manager at Brightwell, John Deegan, had not appreciated the full scope of her belief of not working on Sundays.

She said: "Mr Deegan understood the claimant to have current commitments to her church, but did not appreciate that her religious belief meant she could never work on Sundays. If he had done so the issue would have been explored more fully at that junction.

"There was no express agreement ever arrived at by the parties that the claimant would never have to work on Sundays. On the contrary, she was contracted to work on Sundays."

In delivering the unanimous judgement, Judge Williams added that in requesting to take the whole day off on Sunday, Ms Mba was not expressing a core part of Christian belief.

She said: "While the Claimant's belief is deeply-held, it is not a core component of Christian faith."

She later added: "We accept the Claimant had a genuine belief at the time that her religious beliefs would be accommodated in full, but this was a case of hearing what she wanted to hear.

"The respondent made substantial attempts to accommodate her religious beliefs. We reject the claimant's submission that no 'serious or conscientious' attempts were made to accommodate the claimant."

Yvette Stanley, Merton Council's director of children schools and fFamilies, said: “We are pleased with the outcome of the tribunal.

"As a local authority, we have a duty to ensure our children with disabilities who need weekend care are supported by carers who are familiar with their specific needs."