Absolutely so! The opium trade was roundly condemned in Britain from its very beginnings. See here on objections to the opium trade during the run-up to and course of the Opium War of 1839-42.
Indeed, the notion of an 'Opium War' was quite contemporaneous to the affairs in question. Augustus Lindley's Ti-Ping Tien-Kwoh, published in 1866, asserts at one point that:
The last war, which commenced in 1856, and was ultimately concluded by the ratification of the treaty of 1858, by Lord Elgin in 1860, was equally iniquitous with the first, and in the same manner was originated by the detestable opium smuggling, the seizure of the opium smuggler Arrow being made the pretext for hostilities. Whatever may hereafter be alleged, at the present time but few can be found to deny the fact, that the wars with China have always been waged to force the opium trade, and that by the last one the legalization of that vile traffic was compelled.
While modern perspectives have stressed that in fact the reasoning behind the two wars was actually more complex, with a number of pro-war figures also being anti-opium, Lindley's statement here is illustrative of a contemporary attitude on the subject. What must be noted is that Lindley's attitude on the effects of opium is one tinged with fundamentally imperialistic sentiments:
Forcibly as the moral effect of the general foreign policy of England has been denounced by statesmen, how few have been found to raise their voices in the British senate in protestation against the practical evils which that policy has engendered in the far East, a country abounding in tea and silk, and now paralyzed by opium instead of being enriched by the manufactures of Great Britain... The Ti-pings offered not only satisfactory relations and free intercourse, but every advantage that England could possibly wish for or be benefitted by. Christianity and civilization, as practised among ourselves, would have become morally and physically certain under their rule. The detestable opium trade would have been completely annihilated, and British produce would have taken its place, to the benefit of the Chinese, and the relief of the choked markets and distressed operatives of England.
In this view, British trade could make or break China, and Lindley's critique is that Britain's commercial superiority was being used towards destructive, and not constructive, ends in China. This critique is, however, underpinned by the assumption that British trade could in fact seriously impact affairs across China, an assumption that is not wholly sustainable. Domestic policy was already in a tough spot when foreign opium arrived, and the scale, scope and effect of opium consumption was often wildly exaggerated.
Opium was also the subject of religious critiques. The use of narcotics, and to some extent the Europeans' role in promulgating it, was condemned by missionaries as well – these are quoted in Lindley:
Opium is demoralizing China, and become the greatest barrier to the introduction of Christianity which can be conceived of.
– Rev. W. Medhurst
it is an engine in Satan's hands, and a powerful one.
– Rev. E. B. Squire
As with Lindley, both of these missionary critiques fundamentally present opium not as a moral evil in a transcendent, human sense, but rather as an affront and an obstacle to the objective moral good of Christianity. Some, though, like the Prussian Karl Gützlaff, were happy to 'Let the Devil do the Lord's work', so to speak, by serving as interpreters for opium smugglers in exchange for being able to disseminate religious pamphlets at their destinations. At the same time, there was sometimes a reluctance to blame British smuggling rather than Chinese habits.
...someone shouts out, 'Who sells Opium?' My answer has been, I fear, not a very Christian answer, 'Who smokes the Opium?' I have thus silenced them hundreds of times.
– Rev. Arthur E. Moule, 1902, describing heckling by Qing civilians who associated missionaries with the opium trade
Kathleen Lodwick's work on the subject is somewhat more optimistic on the missionary crusade against opium than the more cynical take of Julia Lovell, but it is fair to say that in Britain they were reasonably successful at criticising the trade. In 1892, Parliament adopted a resolution that regarded the trade as 'morally indefensible' (though to be fair, this was already a commonly-held opinion since the 1840s), and in 1907 Britain negotiated a treaty with the Qing whereby opium imports would be scaled down, reaching effectively 0 by 1914. In the event, however, special exceptions for medicinal opium meant that it would take until 1916 for total exports of opium to drop to 1000 chests a year.
Sources, Notes and References
Augustus Lindley, Ti-Ping Tien-Kwoh: A History of the Ti-Ping Revolution (1866)
Julia Lovell, The Opium War (2011)
Kathleen Lodwick, Crusaders against opium : Protestant missionaries in China, 1874-1917 (1996)