NatWest will cut rates tomorrow by up to 37 basis points for both residential and buy-to-let.
The lender is cutting prices for its new business, existing customers and additional lending products.
It follows cuts from HSBC and a number of other lenders last week.
On Friday, Moneyfacts revealed that the average fixed interest rate had fallen week on week for the first time since the outbreak of the war in Iran at the end of February.
The interest rate reductions at NatWest are extensive and include purchase, remortgage and product transfer for landlords and owner-occupiers.
The largest reduction concerns a free five-year fixed interest rate for the purchase of residential homes at a loan-to-value of 95%, which falls by 37 basis points from 5.76% to 5.39%.
Other products are seeing their scores cut, and many of the price cuts are more than 20 basis points.
Aaron Strutt, product and communications director at Trinity Financial, said: “NatWest is reducing both tracker margins and solutions, which is nice to see as some other lenders have increased their trackers just as they have become more popular.
“NatWest is cutting its two-year fix from 4.75% to 4.65%, undermining Nationwide’s current best-buy deal of 4.66%.
“The mortgage market is still in a difficult situation given the latest news from the Middle East.
“Hopefully we will see further price cuts in the coming days, and no doubt Nationwide will look to undercut NatWest again soon.”