The Loudoun Castle Project aims to create an all-weather resort at the 610-acre site at Galston, East Ayrshire, featuring 450 luxury lodges, 12 glamping pitches, a lake and leisure development, indoor sports facilities and an indoor subtropical water park. Up to 2,500 new jobs could be created.

The site will also feature a new distillery, while Loudoun Castle itself will be stabilised and leading conservation specialists will assess what can be done with the building.

It is anticipated that around 1000 jobs will be created in the construction process for a period of at least five years, with an additional 1500 long-term jobs created through the leisure and retail side of the plan.

Key partners in the Loudoun Castle Project include private investment group EIF, global programme management and construction consultancy Turner & Townsend, global planning consultants RPS and specialist castle and heritage consultant Francis Shaw.

David Mace, chairman of the Loudoun Castle Project, said: “A development of this size and scale will provide Scotland and Ayrshire with significant long-term economic benefits both in terms of jobs and tourism.

“The local community and Kilmarnock and Irvine Valley MSP Willie Coffey are delighted that we have assembled such a strong team of professionals that are committed to turning this vision into reality.

“Scottish tourism has had a great year given the international attention the country has received in 2014 through the Commonwealth Games, Ryder Cup and Homecoming Scotland.

“We are keen to maximise the legacy created, by adding a world-class all-weather leisure facility and a visitor attraction that has real stand out. We will clearly attract new visitors from home and abroad and positively impact Ayrshire, making the whole of Scotland proud.”

Nick Laister, senior director at RPS Planning & Development, which is submitting the planning application on behalf of The Loudoun Castle Project, said: “Since the site was allocated in the East Ayrshire Local Plan in 2010, it has been an aspiration of the Council to secure the future of Loudoun Castle as a major tourism destination.

“Having been involved with the planning of the site since the middle of the last decade, I am delighted to be submitting a planning application for a development that is going to realise that vision and have such a significant positive economic impact on the area.

“This proposal will create a unique, high quality resort in this dramatic location with the restoration of the Grade A listed Castle at its heart.

“We have spent the last 18 months consulting with the local community and refining the plans and we look forward to working with East Ayrshire Council and other local stakeholders to make this hugely important development a reality.”

There are also plans for a residential development featuring a mix of house styles including starter homes, bungalows and three, four and five-bedroom family homes.

Project bosses this week submitted a planning in principle application to East Ayrshire Council for the two-phased development.

If the local authority gives the go ahead, work would begin onsite in 2016. Developers expect the first phase to open in 2018.