The lender cited high business volumes as instrumental in the move, which also sees it abolishing assisted purchase schemes and builder deposits.
Maximum LTVs will be reduced to 70 per cent, with the maximum loan accepted subsequently being pulled back to £300,000.
It is also clamping down on adverse criteria and will not accept any customers with bankruptcy or IVAs incurred in the last three years.
Polly Hughes, head of marketing at Mortgages plc, said: “In common with a number of other lenders, we have recently experienced a rapid increase in new business enquiries.
"We therefore have no option but to adjust our criteria and pricing to keep control over business levels.”
These changes will be effective from 7 April.
