He stood down in 1868 when facing likely defeat by the Liberal candidate David Williams, following the Second Reform Act.

Wynne's father having served as MP for Merionethshire from 1852 until 1865. the 1859 General Election was characterised by allegations of coercion against tenant farmers who supported the Liberal challenger David Williams in an election noted for allegations of coercion.

[4] Wynne held the seat with a slightly reduced majority, and this has been attributed by Ieuan Gwynedd Jones to 'a sense of terror' that had struck the mainly nonconformist tenant farmers.

Some farms on the estate were said, at the time of Wynne's death, to have been held for forty years without an increase in rent.

[1] He was buried in the family vault at Llanegryn and the Dean of Bangor officiated at the funeral service.

[9] In a mark of respect for Wynne, his successor as MP for Merionethshire, Osmond Williams, cancelled all political engagements in the constituency in the week following his death.