Police prepare for Battle of Britain

Security factors are being assessed as Manchester United drew Rangers in the Champions League group stage draw on Thursday.
Fans of the current Scottish league champions rampaged in Manchester following their side's 2-0 loss to Zenit St Petersburg in the 2008 UEFA Cup final.
As a result, United player Gary Neville recently had his plans for a testimonial clash with Rangers at Old Trafford blocked by Greater Manchester Police.
However, Thursday's Battle of Britain draw will now pit both teams against each other home and away which has already prompted UEFA to act to calm security fears ahead of the September 14th Champions League clash at Old Trafford.
A UEFA spokesman said: "On top of the usual delegates, we'll send security officers to both clubs to assess the situation"
"They'll speak to the clubs and police and see how fans will be met at airports and stations - and where they'll stay."
Key figures at both clubs are remaining cool.
United chief executive David Gill told the Guardian: "I don't think it's something we need to worry about. Clearly we have to work with the authorities and Rangers."
"But they will not be bringing the number of fans who came to the UEFA Cup final.
"Alex Ferguson is delighted to be drawn with Rangers. It should be a great occasion."
Gill's opposite number at Rangers, Martin Bain, said: "When we went to Manchester for the UEFA Cup final it was one of the biggest movements of people in Europe with 150,000 descending on the city.
"Going down in those vast numbers was a lot for any club and city to deal with. It was a final.
"It was a minority who spoiled it for the majority but this is a different tie.
"The true Rangers fans will go to Manchester to prove they're a great set of supporters."
In 2003, United played Rangers twice in the Champions League - both games passed without any major trouble.