The mother of a boy with Down's Syndrome has accused the Church of letting her down after her diocese declined to allow her son to make his first Holy Communion.

Clare Ellarby, from the St Mary of the Angels church in Batley, West Yorkshire, said: "I believe it is because of his disability that they won't accept him. I feel very upset my son is being discriminated against and I feel really let down by the Catholic faith."

The catechetical classes for First Holy Communion began in September but Mrs Ellarby explained that she was unable to attend the first meeting with Denum because he was unwell.

When she approached her parish priest, Fr Patrick Mungovin, he explained that the classes were now full and that Denum would have to wait.

When she took her case to Mgr Michael McQuinn of Leeds diocese, Mrs Ellerby claims that he raised questions concerning Denum's understanding of the sacrament but agreed to discuss this with Denum's headteacher at St Mary's Catholic Primary School in Batley.

After several attempts to contact Mgr McQuinn, Mrs Ellarby eventually received a letter from him this month. The letter raised concerns about Denum's ability to concentrate for long periods of time and his understanding based on what Denum's head teacher had told Mgr McQuinn.

He wrote: "While he [Denum] is unable to make preparations this year to the first sacrament he may be able to do in the future when his understanding is better placed."

But Mrs Ellarby said that she feared her son was being discriminated against due to his disability and that "it was his right to make his First Holy Communion".

Mrs Ellarby does not attend Mass every week but she said: "I am from a strong Catholic background and I went to Mass every Sunday as a child. I do go often but not as often as I could because I have Denum and a younger child too."

In a statement, a diocese spokesman said: "Often Baptism is celebrated for babies in order to bring them into the life of the Church but they only proceed to the Sacrament of First Communion when they take part in the Church's life and understand the Church's faith in regard to these Sacraments. Denum's family has not participated in the regular life of the Church or in the preparation preceding First Communion.

"We hope that this will change as Denum grows and we are working with him and his family to help him achieve this."