The interest rate is fixed at 4.54% for the first three years, reverting to standard variable rate at the end of the fixed rate period.
An arrangement fee of £999 will be added to the loan and the product is available exclusively through intermediaries for house purchases or remortgages up to a maximum loan of £200,000 and 75% of value. A basic valuation up to a maximum of £400 will be refunded upon completion.
Peter Doherty, products manager at The Mansfield, said: "We are noticing an increasing level of interest in fixed term mortgages from borrowers wanting to stabilise their repayments over longer periods of time whilst the Bank of England Bank Rate is relatively low.
"This product will ensure The Mansfield remains competitive in the intermediary market as we look to stimulate our mortgage business."