Wentworth entered the English Parliament in 1614 as Yorkshire's representative in the "Addled Parliament", but it was not until the parliament of 1621, in which he sat for the same constituency, that he took part in debate. His position was ambivalent. He did not sympathise with the zeal of the popular party for war with Spain, favoured by George Villiers, 1st Duke of Buckingham, James I's foremost advisor and favourite, but James's denial of the rights and privileges of parliament seems to have caused Wentworth to join in the vindication of the claims of the House of Commons, and he supported the protestation which dissolved the third parliament of James.