An independent Whig, and an advocate for peace with France, Whitbread supported Fox against Pitt throughout the Napoleonic War, strongly opposed its renewal after the return of the emperor from Elba, and interested himself in such measures as moderate Parliamentary reform, the amendment of the poor law, national education, and retrenchment of public expenditure. On April 8, 1805, he moved the resolutions which ended in the impeachment of Lord Melville, and took the lead in the inquiries, which were made, March, 1809, into the conduct of the Duke of York. He was a plain, business-like speaker, and a man of such unimpeachable integrity that Mr., afterwards Lord, Plunket, in a speech on the Roman Catholic claims, February 28, 1821, called him "the incorruptible sentinel of the constitution."

When he moved the articles of impeachment against Lord Melville, Canning scribbled the following impromptu parody of his speech (

Anecdotal History of the British Parliament

, p. 222):

"I'm like Archimedes for science and skill;
I'm like a young prince going straight up a hill;
I'm like—(with respect to the fair be it said)—
I'm like a young lady just bringing to bed.
If you ask why the 11th of June I remember
Much better than April, or May, or November,
On that day, my lords, with truth I assure ye,
My sainted progenitor set up his brewery;
On that day, in the morn, he began brewing beer;
On that day, too, commenced his connubial career;]
On that day he received and he issued his bills;
On that day he cleared out all the cash from his tills;
On that day he died, having finished his summing,
And the angels all cried, 'Here's old Whitbread a-coming!'
So that day still I hail with a smile and a sigh,
For his beer with an E, and his bier with an I;
And still on that day, in the hottest of weather,
The whole Whitbread family dine all together.—
So long as the beams of this house shall support
The roof which o'ershades this respectable Court,
Where Hastings was tried for oppressing the Hindoos;
So long as that sun shall shine in at those windows,
My name shall shine bright as my ancestor's shines,
Mine recorded in journals, his blazoned on signs!"

An active member of Parliament, a large landed proprietor, the manager of his immense brewery in Chiswell Street, Whitbread also found time to reduce to order the chaotic concerns of Drury Lane Theatre. He was, with Lord Holland and Harvey Combe, responsible for the request to Byron to write an address, having first rejected his own address with its "poulterer's description of the Phœnix." He was fond of private theatricals, and Dibdin (

Reminiscences

, vol. ii. pp. 383, 384) gives the play-bill of an entertainment given by him at Southill. In the first play,

The Happy Return

, he took the part of "Margery;" and in the second,