With the prospect of Reserve Bank monetary tightening now being pushed out to 2015, borrower demand for fixed rates has waned. Leading broker groups report that standard variable rate loans are in the ascendancy.Mortgage Choice reported this week that 75.3 per cent of home loans written by its brokers in June were variable rate loans - up from a 12 month average of 72.6 per cent.Mortgage Choice said in a statement that generous discounts being offered on variable rate loans were also driving demand.Aggregator AFG reported that the proportion of standard variable rate loans sold by its brokers in June was 60.3 per cent - up from 58.2 per cent in January and 57.2 per cent in June last year.