Help to buy mortgage with leasehold

Hello,

My partner and I have recently viewed a Bellway home which seems a lovely size as our first buy. With the govenerment scheme of help to buy, we can put done a 5% deposit and they will lend us 20%! It's a really good scheme because we can access lower mortgage rates at around £400. HOWEVER... the property is leasehold. My partner and I have read the horror stories in the news and have asked to buy the Freehold during the purchase. We sought advice from one consultant who said we could add it to our mortgage, but the consultant we are currently dealing with is being very elusive. I am very worried as I have read horror stories of 'merely being a tenant' in your own home. Can anybody offer any advice? With the deposit we've currently got and the price of house, a normal mortgage would set us back £850 a month! Such hard work getting on the property ladder and I feel like the government scheme is fabulous, yet they are almost trapping first time buyers by sending them to these companies who aren't interested in customer satisfaction, but lining their pockets. Your help is much appreciated