With your residency issue, and particular requirement, it might be worth getting independent financial advice.

I’ve pasted links below to the CGT guide and how to find an IFA.

This is the sort of info you will find:-

To work out your Capital Gains Tax you’ll need to look separately at each asset disposed of that’s liable to Capital Gains Tax and in straightforward cases:
Take the disposal proceeds (usually the amount received) and deduct your costs and tax reliefs to work out each gain or loss.
Add together all of your gains for that tax year.
Add together all of the losses you’ve made for that tax year.
Deduct any allowable losses you’ve made that year from the gains to work out the overall gain or loss.
If the overall gain is below the annual tax-free allowance (known as the ‘Annual Exempt Amount’), there’s no Capital Gains Tax to pay. The Annual Exempt Amount for individuals is £10,100 for 2009-10 and 2010-11.
If the overall gain is above the Annual Exempt Amount, you may be able to deduct unused losses from earlier years.
If the overall gain is still above the Annual Exempt Amount, you deduct the Annual Exempt Amount and work out the tax on the balance. The rate of tax is 18 per cent for 2009-10. Follow the ‘Capital Gains Tax rates’ link below to find the rates of tax for other years
References :
http://www.hmrc.gov.uk/cgt/index.htm

http://www.unbiased.co.uk/

In other words, if you made a business out of buying and selling British property, you would be deemed to be running a UK based business and then the sales would be treated like the rent but as it is a single disposal, you are exempt as a non resident.
References :

As a former estate agent (never sold at P.W, as my clients were not interested in living out in the middle of nowhere)
I can only say that if you have bought a property from them either in "La Isla de Condado Alhama" or anywhere else and are worried about your contract with P.W or that you don’t feel they are fulfilling it, or that there is little progress with them, you need to get advice from your lawyer in Spain (if you have one, and I hope you do) Most contracts for off plan properties have a finish date obviously, but also should have a clause which gives the builder a little leeway of around 3-6 months over that date in case he has problems with weather, supplies etc. So say if your property was due to be finished in June you may have a contract that also says it can go over 3 months till Sept. If they have gone over this time, you possibly have right to compensation, so consult a legal professional here in Spain.
Property here is at an all time slow but if P.W had gone under,or there was even a sniff of this happening there would be more evidence out there, and I can’t find any. I speak fluent Spanish, watch Spanish t.v as well as Brit news and I have not found any evidence of what you say.

However Parador Properties HAVE gone into vol. liquidation as you can see from this link:

http://www.calis-beach.co.uk/forum/topic.asp?TOPIC_ID=22929

This llink may be of particular interest to you:
http://www.eyeonspain.com/forums/posts-long-2900.aspx

Good luck any. If anyone can give any real evidence to this questioner that P.W have gone into vol. liquidation, then I apologise for my mistake, but to date I can’t find any evidence.
References :
17 years in Spain, many as an estate agent

The government probably took it for non payment of taxes. But if you seriously want to check this out you better go to that part of Spain and visit the area in person.
References :