I've come to the conclusion that they are just after the best deal for them!
I saw the mortgage broker who works within the estate agent im using to sell my house. I'm reasonably savvy when it comes to mortgages and I have spoken to my existing lender at length about future borrowing when we sell and want to buy another property. As long as certain factors are in place they have verbally confirmed the level of borrowing that we have in mind.
The mortgage broker within the estate agents is saying that my existing lender won't lend me bugger all in addition and I need to jump ship pay a £6.5k redemption and go to a new lender. Bearing in mind my fixed rate deal is up in 10 months! Other things he said completely contradicted what the my existing lender has said to me. Oh and if he does the application for me I have to pay £450 for the privilege.