MSP defects from Scottish Conservatives to Reform at press conference

Addressing the decision to leave the party he joined at the age of 15, Mr Simpson said it was a “wrench”.

Speaking at a press conference in Broxburn, West Lothian, the new Reform MSP said: “It’s fair to say that some of you won’t be surprised to see me here, given that the Scottish Tories have been touting my name as a potential defector for months now.

“So today, I’m giving them what they want, but perhaps not for the reasons that they think

“Leaving the party that I first joined when I was 15 is an enormous wrench, and I’ve been through a lot of soul searching in the past few weeks.”

Mr Simpson said he decided to join Reform UK to “create something new, exciting and lasting”.

The former Tory MSP said: “I’ve joined Reform because we have the chance to create something new, exciting and lasting that puts the needs of people over the system, that asks what is going wrong how we can fix it.”

He added he thought Reform could “help” to remove the SNP from office after 19 years in power.

The former frontbencher was elected in 2016.

This comes as Reform UK leader Nigel Farage unveiled his party's plans to tackle illegal migration at a press conference at London Oxford Airport with Reform chairman Zia Yusuf on Tuesday.

Mr Farage said that Britain would leave the European Convention on Human Rights (ECHR) if he won the next election “no ifs, no buts” in order to carry out mass deportations of migrants and asylum seekers.

The British Bill of Rights would replace the Human Rights Act, which enshrines the convention in law, under Reform's plans. This would only apply to British citizens and those who have a legal right to live in the UK.

Sir Keir Starmer has blasted Nigel Farage as “not serious” as he condemned the pledge.

Sir Keir has warned that doing so would put the country in the same “camp” as Russia and Belarus.

“Let’s be clear: the ECHR underpins key international agreements on trade, security, migration and the Good Friday agreement. Anyone who is proposing to renegotiate the Good Friday agreement is not serious.

“We’re focused on the very serious policies to address this issue rather than a return to the gimmicks, the slogans, the chaos of the previous government,” the Prime Minister’s official spokesman said.

Mr Yusuf insisted the deportation of 500,000 or 600,000 over the course of a five-year parliament was "totally" possible - a plan that would cost an estimated £10 billion over five years.

The immigration crackdown continues to top Reform's agenda, with Mr Farage launching what he called "Operation Restoring Justice" from behind a lectern.