Thousands of Christian families have left refugee camps in Iraq, a senior church leader has reported. He attacked the Iraqi government in Baghdad for failing to help the displaced Christians who are hungry, often sick and in need of places to live.

Chaldean Archbishop Bashar Warda of Erbil, who is overseeing aid efforts in the beleagured country, said numbers of Christian families in the camps had fallen from 120,000 to 100,000. Many families have left the country.

Archbishop Warda was speaking to a delegation to the aid distribution centre in Erbil, organised by Aid to the Church in Need, a Catholic charity that supports persecuted Christians around the world.

He told members of the UK Parliament visiting the centre that there is still a need for homes for the displaced, medical centres, food and pastoral and spiritual support.

He deplored the lack of aid from the Iraqi government in Baghdad, which he said had provided no help at all. This is in contrast to charities such Aid to the Church in Need which helped in Iraq with €10 million donations last year alone.

Warda told the MPs: "We rely on you telling the story of the situation and the importance of Christians remaining, so that the Christians can help be a bridge between the different groups."

As a sign of life in the Christian community in Iraq, which has suffered terrible losses as a result of the Islamic State reign of terror, the delegation attended an ordination service in Ankawa. The new priests included Father Martin Banni, aged just 25, who trained at St Peter's Seminary, Erbil. While many members of Father Banni's family have left Iraq for the US or Sweden, he decided to remain in Iraq to pastor to its remaining Christians.

Head of the Chaldean Church Patriarch Raphael Sako said: "This ordination is a sign of hope – we hope that the refugees will be able to go home soon. Father Martin should be a model of Christ – of courage and sacrifice."

Jim Shannon MP for Strangford, and chair of the All-Party Parliamentary Group for International Freedom of Religion or Belief, said: "It was illuminating, it was heartening, it was humbling. For me, it was an opportunity to see in some places a very thriving Church, and in other places a very persecuted Church, to meet some of those who had to flee with only the shirt on their backs as Daesh descended upon them to do their worst."

Jim Shannon MP described visiting one of the camps. He said: "There were many things that impressed me, but one thing that impressed me greatly was when we went around the camps and I met some of the displaced people was this – they had lost so much, but they had on their walls a picture of the Lord Jesus with the words: 'Jesus I will trust in thee'. For me though it was their faith that was sustaining them, so it was an important visit to make and one that I'll never forget."

Aid to the Church in Need reports that Iraqi Christians are currently in a desperate situation, especially as many aid agencies are pulling out or scaling back their activities.