Due to a petition with over 150k signatures the UK parliament is going to (hopefully but probably not) debate the legal use of weed in the near future.
However why was weed originally made illegal in the UK? A comment on a news article I saw was claiming that one of the reasons was...
"The reason cannabis was made illegal in the first place was to destroy the hemp industry as it threatened the profits of the petrochemical, oil and paper industries. The law was never put in place to protect people as they will claim but, like most things in this day and age, to protect corporate profits. "
Is there any truth in this statement? Or were people at the time just concerned about the health effects?
That's true for the U.S where they had a large textile industry based on cotton and others crops. This of course led to a lot of politicians like William Randolph Hearst to fight for cannabis' illegality but that's not true for the UK. I think you might be mixing the two up
Cannabis prohibition in the UK was mainly an effort to stay in line with other nations' laws.
When cannabis was originally outlawed in the UK, it wasn't even mentioned in the debate. The Dangerous Drugs Act 1925 which prohibited cannabis was a ratification of the Geneva International Convention on Narcotics Control - and cannabis was added to the agenda there by Egypt and Turkey.
In 1945 there were only 4 convictions for possession of cannabis. Essentially, cannabis was banned for no social reason, and no British politicians had any strong feelings about it.
The Wootten Report, published in 1968, describes a history of international debate about cannabis:
Belgium, Germany and the Netherlands drew attention to the use of galenical preparations. Yugoslavia expressed fear that industrial use would be restricted. The League of Arab States asserted that in the Middle East hashish was preferred to other narcotics. Ghana, with support from Brazil, said that cannabis produced anti-social behaviour which was a threat to the whole community and should be controlled as strictly as opium. Venezuela reported that cannabis was a "grave social danger". The U.S.A. pointed out that although cannabis might be merely habit-forming it was very often "only a stepping stone to heroin addiction". India maintained that cannabis products were less noxious than heroin, and cannabis addiction, like alcoholism, did not constitute a serious social problem in that country where marihuana-smoking did not lead on to the taking of heroin. France and the United Kingdom indicated that the cannabis problem was of little concern in their countries
Fear-mongering about the dangers of cannabis to society started well after it was first banned. From the Wootton Report:
In the early part of the period most seizures were of green plant tops, found in ships from Indian and African ports and thought to be destined for petty traffickers in touch with coloured seamen and entertainers in London docks and clubs. By 1950 illicit traffic in cannabis had been observed in other parts of the country where there was a coloured population. In 1950, however, police raids on certain London jazz clubs produced clear evidence that cannabis was being used by the indigenous population; by 1954 the tendency for the proportion of white to coloured offenders to increase was well marked, and in 1964 white persons constituted the majority of cannabis offenders for the first time.
The comment you quoted may well be referring to American legislation.