David Koch urges the Reserve Bank to hold rates, saying households are struggling enough. NewsWire Credit: SuppliedCash-strapped mortgage holders are on the brink with another interest rate hike likely to push many households over the edge. Mr Koch warned another rate hike would be devastating for many households. “Essentially, they’re getting another rate hike when they go to fill up the car.” Camera Icon Compare the Market economic director David Koch says the RBA shouldn’t punish mortgage holders.