UK Google Merchant Centre & displayed product price question - VAT

[Captain Weak Beard]

I'm based in the UK. I've been using Google Merchant Centre recently, displaying ads ONLY to the UK, and it's been great at generating more sales. One problem I've had is that the Google Shopping ads for my products all show the price exlcuding VAT (tax), I checked the product list in Merchant Centre and all the product prices were excluding VAT/tax and I couldn't work out how to fix this, I asked the module developer who couldn't help further then the feed was exporting including VAT/tax.

So I called Google and they said that the only way to fix this is to set Prestashop to display prices as excluding VAT/tax, easy.

 

But.... some of my competitors are also displaying Google Shopping ads ... and their prices are including VAT/tax?!

 

So can anyone explain to me how do I get the product prices in the Google Shopping ads to display the price including VAT/tax so that when my customers click the ad and arrive at my website, that they still see the same price. Currently it looks very bad that my prices are more expensive on my website than they are advertised for in search results.