Former attorney general Dominic Grieve has urged the government to think carefully before creating a new bill of rights to replace the Human Rights Act.

A year since the Conservative Party put forward proposals to replace the act, justice secretary Michael Gove is expected to expand on his plans for the legislation at this week’s party conference in Manchester.

Speaking at a fringe event hosted by human rights group Liberty, Grieve (pictured) said the European Court of Human Rights in Strasbourg is improving - and urged his colleagues to be wary of making any rash changes.

‘Anybody who wants to bring about a change needs to do analysis of the costs and benefits,’ he said. ‘What you will find is the cost is reputational [and] damaging to our standing and reputation.

‘There will still be many occasions when [home secretary] Theresa May will be irritated by an outcome. I was irritated at times when I was attorney general but it is not a reason for ripping up the structure which serves the interests of people in this country so well.'

Grieve conceded the European court is ‘not perfect’ but insisted the current workload far exceeds that estimated when it was created. After the Brighton declaration in 2012, Grieve told delegates that the party was in danger of being ’10 years behind the curve’ in calling for reform.

‘It is quite important we don’t end up fighting yesterday’s battles – the court has gone through a transformation in the last six years,' he said. 

‘Even when the court was in my view not functioning very well it was still producing judgments on hundreds of cases with appalling breaches of human rights which progressively changes how countries work.’

He added: ‘Lots of people are queuing up saying they will not honour their obligations [if the UK leaves the European Convention on Human Rights]. If we withdraw it throws out the question of what message we are sending out.’

Grieve said critics of the HRA and the current system failed to acknowledge the times when the UK Supreme Court has made a decision and not been overruled by Europe.

Even if decision-making were restricted to judges in the UK and the act is replaced with a bill of rights, ’99.95%’ of the time the interpretation will be the same, he added.