Can I contest this valuation as it could increase my capital gains tax?

My brother and I were gifted a house by my mum and stepdad in January 2014. They bought the house in 2004 for approximately £195,000. The value on the land registry title absolute recorded at the time of transfer to me and my brother in 2014 was stated as being 'between £100,001 and £200,000. If my brother and I were to sell the property now for an approximate value of £300,000 how much CGT would we pay? Is it affected by the stated value at time of transfer in 2014? If so, is there any way I can contest this valuation, as it is definitely wrong. The house is in London and is almost certainly above the £200,000 valuation given in 2014 and definitely above the £100,000 valuation. The property has been rented out the entire time it has been owned by my parents or me and my brother.

You can certainly contest this valuation. A house in London bought for £195,000 in 2004 must have been (under normal circumstances) worth a lot more in 2014. You are not bound by what was written on the land registry documents. See www.gov.uk/hmrc-internal-manuals/capital-gains-manual/cg14530 and www.gov.uk/hmrc-internal-manuals/capital-gains-manual/cg16230.