Muslim pupils must study two religions under government plans to tackle extremism in schools following the Trojan Horse plot.

Changes to religious studies qualifications are expected to be set out by ministers next week when the subject criteria for GCSEs is published.

Faith schools are likely to see the biggest impact as they can currently choose to teach their own religion and disregard others.

Under new government plans to tackle extremism in schools, Muslim pupils will have to study two religions

As well as studying at least two religions, pupils will also be expected to debate moral dilemmas in the context of religious beliefs in class.

The modifications to lessons comes after the alleged Trojan Horse plot by hardline Muslims to infiltrate schools in Birmingham.

It was originally sparked by a leaked letter in March this year - now widely believed to be a hoax - which alleged to be from Islamists in the city plotting to seize control of a number of school governing bodies.

Birmingham City Council revealed a month later that it had received 'hundreds' of allegations of similar school takeover plots - some dating back 20 years.

Tahir Alam, chairman of the Park View Education Trust which runs six schools in the city, resigned after he was found to have written a detailed blueprint in 2007 for the radical 'Islamisation' of secular state schools.

The government hopes by tweaking religious studies lesson criteria it will help tackle cultural isolationism and extremism.

But despite this, schools will be able to decide how much teaching time to give each faith - so pupils could spend three quarters of the course studying one faith and just a quarter on the other.

Changes are expected to be set out by ministers next week when the subject criteria for GCSEs is published

Park View School was one of those that was at the centre of the Trojan Horse plot by hardline Muslims to infiltrate schools in Birmingham

Teachers will also have to give sharper focus to the study of faith and steer away from the current method of dividing studies into philosophy and ethics.

While teenagers will be expected to answer questions on ethics with reference to religious beliefs.

The new syllabus will also have an extra option that places more emphasis on the study of religious texts, practices and sources of authority.

However, A-level students will continue to be able to study only one religion if they choose under the new criteria.

The amendments have been broadly welcomed by the Church of England.

Reverend Nigel Genders, the Church of England's chief education officer, told The Times: 'Studying two religions with a further detailed text based study for one of the religions at GCSE will promote depth and breadth and equip students to be religiously literate in today's world.'

Andrew Copson, chief executive of the British Humanist Association, also told the paper: 'It is hugely important that all young people learn about the full range of different religious and non-religious beliefs that are common in society today.

'Such learning makes a vital contribution to respect and tolerance of individuals with different beliefs.'

Mr Copson added that the change is welcome progress but does not go as far as he would have liked.