With a passionate zeal against Roman Catholicism ("I despise such a ridiculous and nonsensical religion" he once remarked), and an intense love of political liberty, he opposed the persecution of Protestant Dissenters.

His first speech in Parliament appears to have been on 22 January 1674, when he inveighed against the Great Stop of the Exchequer, the attack on the Smyrna fleet, the corruption by French money of Charles's courtiers, and the ill-intended ministers of the king.

[1] Anti-French, warmongering alarms which culminated in the "discovery" in 1678 of the first "conspirators" of an alleged Popish Plot to treacherously murder King Charles II and accelerate the accession of his Roman Catholic brother, appear to have affected Russell more than his otherwise sober character would have led people to expect.

On 4 November 1678, Russell moved an address to the King to exclude his brother James (at the time the Duke of York) "from his person and councils" (homes, companionship and correspondence), including removal from the line of succession.

[5] Only six days after this, Russell moved for a committee to draw up a more subdued bill "to secure religion and property [in case of] a popish successor".

On 16 June, he accompanied Shaftesbury when the latter indicted James at Westminster as a popish recusant; and on 26 October, he spoke in the house to move to "suppress popery and prevent a popish successor"; while on 2 November, now at the height of his influence, he seconded the motion for exclusion in its most emphatic shape, and on 19 November physically carried the exclusion bill to the House of Lords.

It was probably at his wish that his chaplain wrote the Life of Julian the Apostate, in reply to Dr Hickes's sermons, defending the lawfulness of resistance in extreme cases.

[1] Russell had no share in the schemes of Whig Lord Shaftesbury after the election of Tory sheriffs for London in 1682; upon the 1683 violation of the charters, however, he began seriously to consider the best means of resisting the King's government.

In October 1682, he attended a meeting at which what might be construed as treason was talked:[1] Monmouth, Essex, Hampden, Algernon Sidney, Lord Howard of Escrick (a cousin of Russell's mother) and Sir Thomas Armstrong met at the house of one Mr Sheppard, a wine merchant.

Monmouth offered to return to England and be tried if doing so would help Russell, and Essex refused to abscond for fear of injuring his friend's chance of escape.

Lord Chief Justice Francis Pemberton, in his summing up to the jury, clearly leant towards an acquittal, thereby offending the King, who dismissed him soon afterwards.

Even Jeffreys, leading for the prosecution, conducted the trial in a sober and dignified manner quite different from his normal bullying style, and, while stressing the strength of the evidence, reminded the jury that no innocent man should have his life taken away.

After the verdict Russell's wife and friends made desperate efforts to save him, making pleas for mercy to the King, the Duke of York, and the French Ambassador, Paul Barillon.

At the time, those sentenced to death by beheading (a method "reserved for [...] aristocrats")[9] were customarily "advised to tip the public executioner in advance.

Even among the bloodthirsty throngs that habitually attended English beheadings, the gory and agonizing display had created such outrage that Ketch felt moved to write and publish a pamphlet titled Apologie, in which he excused his performance with the claim that Lord Russell had failed to "dispose himself as was most suitable" and that he was therefore distracted while taking aim on his neck.

He resigned himself rapidly to accept his fate with dignity while still stating his innocence, but was disappointed in the justice he had received, as laid out in his last letter before his death.

Whigs later commemorated him as a mistreated martyr, supposedly put to death in retaliation for his efforts to exclude James from succession to the crown.