Is it correct in Islam to take a mortgage to purchase a property in this country, given that the Halal mortgages seem to be only for the rich Muslims.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If the loan is a usury-free loan, then this is permissible but if it is a loan with Riba (interest and/or usury) then it is not permissible to take it because this is categorically forbidden, and it is one of the great and most heinous sins. Allah Says (what means): {O you who have believed, fear Allah and give up what remains [due to you] of interest, if you should be believers. And if you do not, then be informed of a war [against you] from Allah and His Messenger. But if you repent, you may have your principal - [thus] you do no wrong, nor are you wronged.} [Quran 2:278-279]

The Prophet said: “Allah has cursed the one who consumes Riba (i.e. usury or interest), the one who gives it to others, the one who records it and the one who witnesses it (its transaction).” ; and he said: “All of them are equal in sin.” [Muslim].

Therefore, a person should fear Allah as He should be feared and stay away from anything that is forbidden. If one does so, Allah will solve his/her problems and will make a way for him/her to get out from every difficulty. Allah Says (what means): {And whosoever fears Allah and keeps his duty to Him, He will make a way for him to get out (from every difficulty). And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allah, then He will suffice him. Verily, Allah will accomplish his purpose. Indeed, Allah has set a measure for all things).} [Quran 65:3]

Allah knows best.