He sat in the House of Commons from 1846 to 1857 for East Sussex, and thereafter suffered a series of electoral defeats as he unsuccessfully challenged the political power of the Duke of Rutland in North Leicestershire.
[12] However, the canvassing returns showed that he had little support, and that voters preferred the High Church stance of Lord John Manners, son of the locally powerful Duke of Rutland.
[12] His agents, who included both Conservatives and Radicals, abandoned the campaign in mid-February when they realised that they could secure less than 200 votes in the whole county,[12] and Manners was elected unopposed.
He appeared at the hustings on 8 March to explain his withdrawal, and was congratulated by Manners for avoiding "what, in Parliamentary language, would have been a frivolous and vexatious opposition".
[17] Sixty police officers attended, but despite breaking many heads they were unable to restore order, and the gates of the market hall were closed to further voters.
[20] Polling was taking place in the village's Roman Catholic schoolroom, and Frewen's supporters realised that he was losing, and tried to stop his opponents from voting.
Police tried to protect voters, but were driven back into the schoolhouse, where rioters broke all the windows and threw stones at those inside, as well as trying unsuccessfully to seize the polling books.