Halifax mortgage - Is it must to choose solicitor on their panel?

Hi,

Considering applying for a Halifax mortgage for purchase of a new build (under development) with 70% LTV (can go down to 60% depending on the standard valuation).

Wanted to know if:
1. It is compulsory to choose a conveyancing solicitor from their panel?

Have read on the forum that Nationwide valuation is usually conservative (close the value of the cheapest sale price of same type new builds).

2. Is it the same / similar case with Halifax too?


Thanks in advance.