Pedley went to Jamaica about 1785 at the expense of his brother Robert Deverell and entered the office of the Wildman brothers, agents of William Beckford. There he ‘contrived to undermine their influence and to succeed them in the management of the West India estates’.
The death of a ‘near relation’ obliged Pedley to return to Jamaica in November 1803. Having been chosen a member of the Waterford election committee he sought leave of absence through his brother, but this was refused as creating an undesirable precedent.
In 1805 Pedley bought Beckford’s estates in Bedfordshire, Buckinghamshire and Hertfordshire, for £75,000,
Pedley did not obtain a seat in the election of 1806, but in that of 1807 he contested Saltash on Beckford’s interest; after a double return, he petitioned successfully. When Beckford decided to sell his interest, Pedley naturally urged him to retain it, but in vain. He had to vacate his seat when Beckford sold his burgages in 1809. No speech by him is known. The Whigs were out of touch when they listed Pedley as a Member of whom they were doubtful in March 1810: he had been out of the House nearly a year. Despite this he was also reported as voting with ministers on 23 Jan. and 5 Mar. 1810, possibly mistaken for Prendergast, his successor at Saltash. Pedley died 22 July 1838, aged 76.
