advice on getting a mortgage on 20k a year

hello all,

i am on 20k a year and am looking at buying a studio flat for 140k

i currently have 11k in isa and could get 5k together if i needed to from my mum and dad or using credit cards but i would rather not do this.

i am saving 900 a month at the moment.

can anyone give me advice on getting this flat for 140k using these factors or if i can't have this what i should do over the next year to get the best mortgage.

thanks very much in advance