Thousands attended a Mass and rally in London yesterday, to celebrate immigration and call for an amnesty for illegal immigrants.

The Strangers Into Citizens campaign was joined by faith leaders, immigrants from across the world, community activists and church groups in a gathering in Trafalgar Square, central London.

The campaign is calling for a two-year work permit, without access to benefits, for “irregular” migrants – refused asylum seekers or visa overstayers – who have been in the country for four years or more.

Addressing the rally, the leader of Catholics in England and Wales, Cardinal Cormac Murphy-O’Connor, said immigrants living and working in the country deserved to be treated with “fairness, with justice and with dignity”.

He said: “Our Government and the governments all over the world must treat migrant workers with justice and with dignity.

“That is why I am so glad to be associated with fellow Christians and people of other faiths and with politicians who are determined to see that before long these people who we say are strangers in fact become citizens.”

The rally, attended by thousands, came after a Mass at Westminster Cathedral for migrant workers.

The multilingual Mass, attended by around 3,000 worshippers, came on the feast day of St Joseph the Worker. It began with a procession of parishes and faith groups, and included music from Africa and Latin America. Intercessions were read in six different languages – Romanian, French, Portuguese, Arabic, Yoruba and Tamil.

In his homily, Archbishop Kevin McDonald of Southwark, noted the complexity of migration in the modern world.

“The migration of peoples has always been a feature of human life and is complex. Forced migration and, at its worst, ethnic cleansing, constitute some of the darkest pages of human history and the darkest aspects of modern times. But the movement of peoples can also be a source of great enrichment…The Vatican document Erga Migrantes Caritas Christi speaks of the enhanced experience of catholicity that can be the fruit of different ethnic groups coming together as a result of migration. Certainly we can bear witness to that in our parishes, schools and communities in London. We must thank God for that.”

Archbishop Kevin McDonald of Southwark referred to the special role that the Catholic Church plays in pastoring to the needs of migrant communities in London and said that Catholic parishes needed to celebrate ethnic diversity.

“In the Church, a key role of ethnic chaplaincies and of Catholic parishes is both to integrate new ethnic groups into the already existing community and also to create space to explore and celebrate ethnic diversity, culturally and liturgically. This is a delicate task and a continuing challenge and opportunity for our dioceses and parishes. A positive way of expressing it is in terms of the sharing of gifts, being generous with what we, the host nation, have received and being receptive to what people from other cultures have to offer us. After all, we already share in the gifts God bestows on the Church.”

“For this reason,” Archbishop Kevin McDonald continued, “the Catholic Church has a unique and distinctive contribution to make to the social cohesion of our society. This is true of our parishes and also very much of our schools. We see all humanity as created in Christ. We seek to strengthen the unity of the Catholic Church. We seek greater unity with all other Christians…..we seek to dialogue with members of other religions, trying to identify and explore in a positive way the values we hold in common. And we reach out to all people of good will, and all of this contributes significantly to social cohesion and peace in the world.”

At the end of the Mass, Cardinal Cormac Murphy-O’Connor, Archbishop of Westminster expressed his hope that migrants in London would feel welcome in the capital and realise the depth of solidarity that Catholics had for them.

“Here we are from all over the world, Christians together, saying we are all on the side of migrants. We want all of you to be at home here…. I want all of you who are here today to know how much we welcome you, migrants who are worthy of dignity and a place in our country. ”

Cardinal Cormac Murphy-O’Connor also pointed to concrete action being taken by the Catholic Church in London to help migrants.

“It is a time not just for words but for deeds. In our own catholic community we are beginning to do things for migrants. The Sisters of Mercy are opening a home for trafficked women, the Brothers of John of God are opening a house for migrants to help them with English and to find a job.”