An evangelical Protestant minister has lambasted the Rev Ian Paisley for being driven by "ego and the pursuit of power" and has accused him of betraying his community.

The Rev Alan Clifford has written to the former DUP leader telling him that the North would have been a far better place had he stayed with religion and not strayed into politics.

Clifford, the pastor at Norwich Reformed Church urged Paisley to "repent for his sins" and said that he prayed that young ministers "will not be tempted by your example".

The English pastor first met Paisley 40 years ago. They became friends after supporting each other's views on opposing ecumenism.

Clifford recently caused controversy when he said that while he had no connection with the BNP he agreed with its leader, Nick Griffin, that Islam was "a monster in our midst".

Clifford told the Sunday Tribune: "Dr Paisley betrayed the Protestant people of Northern Ireland when he did a U-turn on sharing office with unrepentant terrorists. I am very sad to say this because I had previously admired him very much as the leading champion of Protestants in the UK.

"Dr Paisley's ministry began with every good intention but the pursuit of power and glory – rather than truth, honour, and justice – became the driving force in his political life. He became ego-driven.

"There is no other explanation for him adopting a political arrangement that he severely castigated so many other Northern Ireland politicians in the past for supporting. Dr Paisley is open to the charge of hypocrisy."

By mixing the roles of pastor and politician, the DUP leader had "violated the word of God", Clifford said. "When I speak to Dr Paisley's former supporters, the sadness that he has caused is written all over their faces. Had he restricted his obvious gifts and energy to the gospel and giving pastoral care, Northern Ireland would have been a better place."

The Norwich pastor wrote in his letter to Paisley that it was inappropriate for a minister like Paisley to take a seat in the House of Lords. As of yet, he has received no reply.