[2] He is reported a descendant of Arthur Plantagenet, 1st Viscount Lisle, KG (died 3 March 1542) through his paternal line.

He advertised that he would contest the Sussex county seat, asked Mad Jack Fuller to help him make an opposition at Lewes and stood at Steyning.

In the 1761 general election, opposition did not press to a poll at either Sussex or Lewes, at Steyning Medley received only three votes out of about 200 but he came third at Seaford.

His position at Seaford remained strong, and in 1767 Thomas Pelham suggested to Newcastle that it would be wise to adopt Medley at the forthcoming general election.

Newcastle did not want him at Seaford but was willing to return Medley for any other of his boroughs, ‘upon an assurance of his friendship and disposition to act with me in Parliament’.

Medley however declared ‘that he was an independent man, with a large fortune, and wanted nothing for himself or his family, and that he would never promise anybody how he would vote in Parliament’ and made it clear that he would stand only at Seaford.