The number of products on the market to service the growing interest in buy-to-let mortgages has risen to highs not seen since 2008, according to Moneyfacts.

Research into buy-to-let product numbers show that the number of products on offer in July 2013 increased to 466, but that today the number has risen by 42.7% to 665.

At the same time, average interest rates charged for both fixed and variable deals have fallen to the lowest levels ever at 4.17% for the average fixed rate and 4.03% for the average variable rate.

Sylvia Waycot of Moneyfacts said: “Lender interest in the buy-to-let market may be fuelled by the knowledge that it falls outside of the recent Mortgage Market Review.

“This makes the process of granting any buy-to-let mortgage quicker and simpler as it is not subject to the new affordability criteria that is starting to clog up the mainstream mortgage market.

“In addition, the new pension regime means that retirees could consider buy-to-let as a way of supplementing their income instead of purchasing an annuity.

“Help to Buy is attracting potential borrowers into the housing market, but the advent of MMR is acting almost like a contradiction, putting the brakes on the process, and the funding element, although sensible, is making it harder for some to get onto the housing ladder.

“Ultimately this all points to the buy-to-let market being here to stay and to remain attractive to lenders, hence the surge in products on offer for landlords who seem assured of a healthy supply of tenants.”