Image caption At your service: The prime minister visits the Royal Welsh Winter Fair at Llanelwedd

Boris Johnson has launched the Welsh Conservatives' manifesto for the general election.

The prime minister, speaking at Bangor-on-Dee racecourse, Wrexham, has promised to "unleash a tide of investment".

Mr Johnson had returned to the Clwyd South constituency, which he contested in 1997.

It follows the publication of the Conservatives' UK-wide manifesto in Telford, Shropshire, on Sunday.

"I started this project 22 years ago," he told the audience, adding that it was "absolutely vital that we get a Conservative elected here".

Mr Johnson said the Tories had high ambitions in Wales, including resolving the long delays at the Brynglas Tunnels along the M4 at Newport.

He said the tunnels were blocked "like the nostrils of the Welsh dragon", adding his party would be the "Vicks inhaler".

The visit to Wales began in Powys with a bid to court the farming vote at the Royal Welsh Winter Fair in Llanelwedd, joking how Jeremy Corbyn and Labour would "fleece the entire country".

He said the Brexit deal he had secured with the European Union would keep farming "absolutely protected" and enabled his party to find more markets.

Mr Johnson said his party would also back the Welsh steel industry.

The Marches Growth Deal includes a specific focus on improving cross-border road infrastructure.

In October, the UK government announced £55m over 15 years for a Mid Wales Growth Deal, which followed the £500m Cardiff City Deal, the £115m Swansea City Deal and the £120m North Wales Growth Deal.

Speaking before the visit, Mr Johnson repeated his plan "to get Brexit done" in order to "unleash this domestic agenda and deliver our exciting plans for Wales".

The party's UK manifesto included a specific section on Wales, which promised the country "major investments" in infrastructure and industry if the Tories win the general election.

It included some previous announcements, such as plans for a West Wales Parkway station outside Swansea, and promises on devolved issues that are the responsibility of the Welsh Government, such as delivering a new M4 relief road.

Other policies that apply to Wales include:

20,000 more police officers across Wales and England

A "triple tax lock", ruling out increases in the UK rate of income tax and National Insurance, as well as VAT, for five years

Raising the National Insurance threshold to £9,500 in 2020, with an ambition to raise it further to £12,500

Tighter immigration controls

In a statement released ahead of the Conservatives' Welsh manifesto launch, Mr Johnson said: "With a Conservative majority government, we will improve connectivity and infrastructure across the whole of our country."

He said the Marches Growth Deal would "make a real difference for people on both sides of the border".

He added: "Labour has a rotten record in Wales and has let down people across Wales badly, from healthcare services to a lack of investment in transport networks. The Conservative party will put that right.

"The Welsh dragon will roar louder than ever before."