The Christian former governor of Jakarta, Basuki Tjahaja Purnama, will withdraw an appeal against his controversial two-year prison sentence over claims that he insulted Islam, saying that has decided to 'forgive and accept'.

The decision by Purnama, who is better known as 'Ahok', was confirmed at an emotional press conference with his younger sister, Fify Letty Indra, who is also a member of his legal team, and his wife, Veronica Tan.

It follows the jailing in May of Ahok, who was given a longer-than-expected term in a ruling that critics fear will embolden hard-line Islamist forces to challenge secularism in Muslim-majority Indonesia.

At a press conference in Jakarta, his wife cried as she read out a letter her husband wrote in prison.

'It isn't easy for me...but I've learnt to forgive and accept all of this if it is for the benefit of the nation and the country,' he wrote.

In the letter, Ahok called for an end to protests in favour of his release. 'It is not right to continue to protest and hold demonstrations in the name of the process that I am going through at the moment,' he wrote.

His wife backed the decision not to appeal. 'The children and I, along with the whole family, we are going to try to support him in his struggle,' she said.

The charge related to a reference by Ahok to a Quranic verse in his re-election campaign last September. His opponents had used the verse to argue that Muslims should not be led by non-Muslims; Ahok said they had used it to trick people into voting against him.

An edited version of his speech was posted online and went viral, sparking mass demonstrations against him including one that drew around half a million protesters.

Ahok lost the election in April to a Muslim rival. As a Christian and ethnic Chinese, he is doubly disadvantaged in Indonesia's predominantly Muslim society, in which Christians are increasingly under pressure.