Coptic Pope Tawadros II is urging young Copts to 'fight for what is right' and vote against same-sex marriage in Australia's forthcoming plebiscite.

Addressing around 1,000 young people on Friday evening, the head of the Coptic Orthodox Church in Egypt told them that 'family equals "father and mother"' in a rally at the International Convention Centre in Sydney Harbour.

Many Copts have fled oppression in Egypt during the last few decades to make their homes in Australia and Tawadros's visit is aimed at supporting their religious identity.

He said when he touched down in Australia: 'According to the Holy Bible, when you read either in the Old Testament or the New Testament, there is no – at all – same-sex marriage.

'Therefore, this marriage is completely refused from the Christian faith.'

Tawadros's comments comes as conservative Muslim leaders say they are afraid to join the debate on gay marriage for fear of being labelled extremists, including by Christians who share their opposition to the move.

Ali Kadri, from the Islamic Council of Queensland, warned many imams and community leaders, who he said represent 'the vast majority of the Muslim community', were refusing to speak out.

Kadri told the Guardian there was a mixture of views among Muslims, conservatives 'are afraid to express their concerns because they're worried they'll be labelled as extremists or terrorists'.

He said: 'It's not those that support the "yes" side that conservative Muslims are afraid of – ironically they are afraid of Christian conservatives who themselves support the "no" side.'

He added: 'Muslims have been flavour of the day for a long time and will come back on to the hit list [if same-sex marriage is legalised]. Although they agree on marriage, there is no sympathy or favours for Muslims [among the Christian right].'

Despite this the Council of Imams Queensland president, Yusuf Peer, has publicly opposed legalising gay marriage and the Australian National Imams Council issued a statement saying marriage was only between one man and one woman.

'This has been the view held by all major faiths including the traditional Judaeo-Christian beliefs and other traditions throughout human history,' the statement said.

'Islam also explicitly and unambiguously states that marital relationship is only permissible between a man and woman; any other marital relationships are Islamicly impermissible.'