I'm sure if you're looking for a mortgage you've probably heard about the 10 year fixed rate Mortgage from The Chelsea they're offering to fix for 10 years at an interest rate of 3.99% you can find out more here:

Mortgages | 10yr-fixed-70ltv-3060.xml | Chelsea Building Society

For those who prefer certainty, with protection against fluctuating interest rates. Your interest rate is fixed for 10 years.

you need to have a deposit of at least 30% and there is a product fee of £1,495
(£195 of this fee is payable on application and is non refundable, £1,300 is added to your mortgage on completion).

The Independent has done a little more about 10 Year Fixed Rate Mortgage - 70% LTV here:

Spotlight On: Chelsea's 10-year fixed-rate mortgage - Mortgages, Money - The Independent

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The Chelsea Building Society also have a 5 Year Fixed Rate Mortgage - 70% LTV that is worth a look, it has an interest rate of 3.29% you still need a deposit of 30% and the same setup fee costs the same at $1,495:

Mortgages | 5yr-fixed-70ltv-3054.xml | Chelsea Building Society

The 5 year is actually a lower interest rate than their 2 year 20% deposit.

you can see other Chelsea's Building Society mortgage products here: Mortgages | Great Value UK Mortgages and Mortgage Products | Chelsea Building Society