Mortgage issues with ex–local authority flat in Zone 1 — two lenders declined, broker says walk away. Should I?

Hoping for some advice from anyone experienced with ex–local authority / concrete construction flats in London.

I’m trying to buy a Zone 1 ex–local authority flat in a modernist 10-storey building (full concrete construction, not a panelised system like LPS). It’s honestly my dream place. I assumed that because it wasn’t LPS or anything structurally unsafe, it wouldn’t cause major issues with lenders.

However, both HSBC and Halifax have declined the mortgage after valuation. The wording was essentially the same:

• They won’t accept it as suitable security because it’s a high/medium-rise block of public sector origin.

• It’s in-situ concrete construction, which they say has “limited marketability”.

• It’s above commercial units (off licence, salon, pharmacy).

• They think the estate location and the busy road reduce saleability ( in London ?? It sits 2 min away from a underground which is a dream )

My broker is now advising me to walk away, and this is actually the second time I’ve been told to give up on this property. But it’s really the flat I want, so I’m struggling with whether to keep trying another lender or accept that this is likely a dead end.

For context:

• It’s not LPS, no known structural issues.

• I already have a broker involved.

• The block is fully concrete and architecturally modernist.

• Zone 1, ex-council estate, 10 floors with shops underneath.

Has anyone been able to get a mortgage on similar properties? Should I keep looking for a more flexible lender (e.g., smaller building societies), or does the combination of factors mean most mainstream lenders will refuse?

Really appreciate any advice — I don’t want to throw more time and money at something that’s fundamentally unmortgageable, but I also don’t want to give up without knowing all the options.