So having been denied access I sent an email to find out why, I was a little miffed:

To: help@national-lottery.co.uk
date:    27 April 2012 21:04
subject:         I am inside the UK - your GeoIP functionality is broken.
mailed-by:       gmail.comGood evening,

Your GeoIP function is broken - I live in Watford so I am definitely
in the UK and yet you are deciding that I can't access your website.

I wanted to buy some tickets for the Euro draw, but due to you
sub-standard system I am unable to.

Turn it off or make it work - it's your problem not my ISPs, after all
they had nothing to do with you using it in the first place so don't
pass the buck to them.

I look forward to your unhelpful stock reply.

Regards

And of course I got a response:

Dear

Thank you for your email dated 28 April 2012. I am sorry to hear of
the difficulties that you have experienced logging in to your account.

Please may I ask you to confirm which internet service provider that
you are using and if I may also I ask you to provide us with your IP
address?

If you are unsure how to find this, please copy and paste the below
link in to your web browser:

www.whatismyipaddress.com

If you require any further information please do not hesitate to contact me.


Yours sincerely


National Lottery Customer Care Team
Ah - I thought, now I can see where they think I am, so I went to the indicated website and found out where they thought I was - needless to say I was not surprised:

So I let them know my results:

Date: 28 April 2012
Subject: Re: Response from The National Lottery (Ref:NL399976)

Thank you for your response Lesley.My external IP address is 80.0.175.nnn

The website you linked to has this information :
'IP Information: 80.0.175.nnn
ISP:Virgin Media
Organization:Virgin Media
Connection:Broadband<http://whatismyipaddress.com/broadband>
Services:None Detected <http://whatismyipaddress.com/ip-services>
City:Watford
Region:HertfordCountry:United Kingdom'

Which shows me as being in Watford, I have just tried logging in to the
national lottery website and have once again been refused - so what's going
on?

Regards

And here is their reply:

Thank you for your further email dated 28 April 2012 with regard to
accessing your online National Lottery account whereby you have
advised your IP address.

This matter has been escalated for review by our technical team.

When queries are under review, our scheduled response time is within
ten working days.  However please be assured that every effort will be
made to contact you as soon as possible.

For the moment, I apologise for any inconvenience caused to you while
you await our response.

Yours sincerely

National Lottery Customer Care Team

Excellent I thought - escalated to the technical team, now we'll get some answers...