Background: George Galloway (born 16 August 1954) is a British politician, broadcaster, and writer. Between 1987 and 2015, with a gap in 2010-12, he represented four constituencies as a Member of Parliament, elected as a candidate for the Labour Party and later the Respect Party. After becoming the youngest ever Chairman of the Scottish Labour Party in 1981, he became General Secretary of the London-based charity War on Want in 1983, remaining in the post until elected as MP for Glasgow Hillhead (later Glasgow Kelvin) at the 1987 general election. In 2003, Galloway was expelled from the Labour Party, having been found guilty by the party's national constitutional committee of four of the five charges of bringing the party into disrepute, including having called on Arabs to fight British troops.
Context: On 22 April 2003, The Daily Telegraph published news articles and comment describing documents found by its reporter David Blair in the ruins of the Iraqi Foreign Ministry. The documents purported to be records of meetings between Galloway and Iraqi intelligence agents, and they stated that he had received PS375,000 per year from the proceeds of the Oil-for-Food Programme. Galloway completely denied the claims, and pointed to the nature of the discovery within an unguarded, bombed-out building as being questionable. He instigated legal action against the newspaper, which was heard in the High Court on 14 November 2004. On 2 December, Justice David Eady ruled that the story had been "seriously defamatory", and that The Daily Telegraph was "obliged to compensate Mr Galloway ... and to make an award for the purposes of restoring his reputation." Galloway was awarded damages of PS150,000 plus, after a failed appeal in 2006, legal costs of about PS2 million. The libel case was regarded by both sides as an important test of the Reynolds qualified-privilege defence. The Daily Telegraph did not attempt to claim justification (where the defendant seeks to prove the truth of the defamatory reports): "It has never been the Telegraph's case to suggest that the allegations contained in these documents are true". The newspaper argued that it acted responsibly as the allegations it reported were of sufficient public interest to outweigh the damage caused to Galloway's reputation. The trial judge did not accept this defence, noting that comments such as Galloway being guilty of "treason", "in Saddam's pay", and being "Saddam's little helper" caused him [the judge] to conclude that "the newspaper was not neutral but both embraced the allegations with relish and fervour and went on to embellish them"; additionally, the judge ruled, Galloway had not been given a fair or reasonable opportunity to make inquiries or meaningful comment upon the documents before they were published. The issue of whether or not the documents were genuine was likewise not at issue at the trial. Oliver Thorne, a forensic expert who had been earlier hired by Galloway's lawyers, later stated "In my opinion the evidence found fully supports that the vast majority of the submitted documents are authentic". He added "It should be noted that I am unable to comment on the veracity of the information within the disputed Telegraph documents, whether or not they are authentic." CANNOTANSWER
Question: Why did he take legal action?. Whats the answer?

they stated that he had received PS375,000 per year from the proceeds of the Oil-for-Food Programme.