A2 Charge and new stamp duty enquiry (bit complicated)

Hi, this might be a bit complicated, so I'll try and keep it brief and would be so grateful for any advice.

Currently my husband and I live together in a property that I own. I brought the property after we were married and had to get the mortgage in my single name because my husband was still on a mortgage with his ex wife (even though the court ordered her to 'use her best endevours' to remove him from it. She basically never applied for him to be taken off and we cannot force her to do so).

Also, she continually threatens to default on the joint mortgage they have together and we were concerned about my husband owning another property in case she did default and the bank tried to come after our property to get their money.

So recently I phoned First Direct (who I have my current mortgage with) to see if I could borrow any more money on my own so we could maybe buy a bigger place and they asked why I was not applying for a joint mortgage with my husband. I explained all of the above. First Direct (the wonders that they are) explained to me that we could apply for an A2 Charge on their mortgages, whereby both my husband and I would be jointly responsible for the mortgage (so both our salaries are taken into account - hurrah) but only my name would be on the deeds (thereby the property would not actually belong to my husband - meaning SHE could have no claim on it or it could not be seen as an asset of my husbands if she defaults). Brilliant, all our woes are over. First Direct did a mortgage interview for us both as joint mortgagees (is that a word?) and have sent us a decision in principle with an amount that means we can now buy a bigger property (we are currently in a small 2 bed flat and would like to upgrade to a 2 bed house). So all is good and off we go looking at properties.......

However, we have now discovered that stamp duty has gone up if the property purchased is a second home. The price of properties we are looking at would mean a jump from about £6,000 stamp duty to £16,000!!! Because this would technically be a 2nd home for my husband as he already 'owns' another property. I put the word 'owns' in inverted commas because it is in it's loosest term. He basically is on the mortgage for a property he cannot live in, cannot sell and cannot remove himself from. Sigh.

But, and this is my question, if we did the A2 Charge mortgage with FD, whereby he would be on the mortgage but not on the deeds, would we still get hit with the higher rate of stamp duty as technically he would not own the new house we brought. He would be responsible for paying the mortgage but have no legal ownership rights to the property? (We are aware we need to see a solicitor to draw up a declaration of trust regarding this).

Anyone have any clue where we stand with this? So sorry for long winded question, but finding it hard to find any solid info online as A2 charge mortgages are very rare and the higher rate of SD only came in recently so there doesn't seem to be any info out there at moment for this set of circumstances.

Thanks in advance for any help or advice.