The advice given by themas is absolutely correct, you are a long way off losing the property and probably never will, particularly if you have children under 18, keep your mortgage provider informed every 3 months or so of your position, they may decide to obtain a charging order against the property which is done in two parts, for which there would have to be a court hearing, make sure this does not have a condition that the charging order can be used as the basis for an order for sale, it will mean they will get their money which is outstanding if the property is ever sold.
Check your position with benefits if your partner is out of work and having made an offer that you can afford, ignore what the mortgage provider says and ensure you continue to make these payments on a regular basis. Your partner is behaving in a responsible manner during a difficult period and this will be recognised.