Simpson announced his move as he appeared at a press conference in Scotland with Reform leader Nigel Farage.
Most Recent Articles
'I need to look after myself' - Draper out of US Open with arm injury
British number one Jack Draper withdraws from the US Open because of an arm injury.
Tony Blair will take part in meeting on US plan for post-war Gaza
It is thought discussions at the White House will include how to get more humanitarian aid into the Palestinian territory.
What we know about the Minneapolis Catholic school shooting
Two children aged eight and 10 have been killed and 17 more people have been injured.
What is on the table at Trump’s Gaza meeting?
And Labour is back to talking about Brexit.
Tommy Robinson will not be charged over St Pancras incident
British Transport Police said prosecutors concluded there was not enough evidence to bring charges in connection to the incident.
'Something I've wanted my whole life' - Lake makes British history with 2m leap
Morgan Lake makes history as the first British woman to clear two metres in the high jump at the Diamond League Final in Zurich.
Ryanair to increase oversized bag bonus for staff
Michael O'Leary told the BBC the change would come in November, and that he made no apology for it.
'I'm not a wild animal', says alleged sex attacker
Hadush Kebatu, an asylum seeker staying at The Bell Hotel in Epping, denies five charges.
Is Trump right about wind power and UK energy bills?
President Trump has suggested this week that wind power is the reason for rising energy bills in the UK. BBC Verify's Ben Chu takes a look at the data.
Russian drone attacks cause massive power cuts, Ukraine says
More than 100,000 homes are without power after the latest Russian strikes on energy sites, President Zelensky says.
6-2 6-1 in 60 minutes - dominant Raducanu races into third round
Emma Raducanu overcomes a potential banana skin as she clinically beats Indonesian qualifier Janice Tjen to reach the US Open third round.
Solar-powered postboxes being rolled out across UK
Royal Mail says the revamped design will help it compete in small parcel deliveries.
Lib Dem leader Ed Davey to boycott Trump state banquet over Gaza
The Lib Dem leader says he wants to send the president a message that he has the power to end the crisis.
Reform rows back on possible child migrant deportations
Nigel Farage has now ruled out the suggestion, after the party's former chair said it could happen.
Cardi B denies scratching and spitting on security guard
The rapper denies attacking the guard, who is suing for assault, but admits she did swear at her.
Taylor Swift's engagement ring, and the celebrity trend for big rocks
Georgina Rodríguez, Dua Lipa and Zendaya are just some of the recently-engaged stars with standout rings.
UK to lose out on new drugs that are available in EU countries, pharma firm warns
The claims from pharmaceutical giant Novartis comes amid a row over drug pricing deals.
'Really tough decision' - US captain Bradley will not play in Ryder Cup
Captain Keegan Bradley decides against including himself as a playing member of the United States Ryder Cup team to face Europe next month.
'Punk rock' dinosaur with metre-long spikes discovered
The animal has come as a surprise to experts, who now have to rethink how these armoured dinosaurs evolved
Patients struggle to get weight loss drug ahead of price rise
The drug's US manufacturer has asked UK distributors to stop taking orders from pharmacies until next month's price increase.