The Advertising Standards Authority has upheld a complaint against the Palestinians' diplomatic mission to the UK for displaying a map which included the whole of Israel as part of Palestine.
The map, decked in red, green and black, the colours of the Palestinian flag, appeared on a tourist section of the mission's website called "Discover Palestine".
Barrister Jonathan Turner, head of the Zionist Federation's legal group and one of six complainants to the ASA, said that the authority "should be congratulated on its careful and impartial scrutiny.
"Too often we are on the defensive against attacks on Israel and Israeli organisations. As this ruling shows, those who attack us should pay more attention to failings in their own camp."
The mission - referred to in the ASA report as the Palestinian Embassy UK - argued that the map referred to "historic Palestine" in 1948 and that it had changed the colour coding to demarcate Israel from the Palestinian territories.
But the ASA noted the use of the Palestinian national colours and the lack of any reference to the state of Israel. "We considered that the average consumer would infer from the map and the linked information that the total area represented by the map was the Occupied Palestinian Territories," it concluded.
It also upheld complaints against the website for implying that Haifa, Jaffa and all of Jerusalem were part of the Palestinian territories.
Entries on Hebron and Bethlehem also breached the advertising watchdog's code because they failed to provide information on travelling restrictions to the two destinations that should have been given to potential tourists.
Mr Turner said: "We will examine the revised website as well as other advertising and if necessary make further complaints."
Maps of Israel and Palestine have increasingly become a bone of contention with an increasing number of cases referred to the ASA.
The Israel Government Tourist Office was forced to pull an advert last year after the ASA said it showed the Western Wall as part of Israel rather than disputed East Jerusalem.
A Palestinian tourist advert also fell foul of the ASA this year for appearing to lay claim to the whole of Jerusalem.
Now the IGTO is the source of a fresh complaint after an advert in the Guardian's Weekend Magazine the Saturday before last.
The Palestine Solidarity Campaign, in a notice on its website, said: "It includes a map where there is a very faint dotted line separating Gaza, Golan Heights and the West Bank from Israel.
"It is so faint as to be virtually unnoticeable and the West Bank is not labelled as occupied Palestinian territory nor the West Bank but instead labelled as Samaria and Judea."
Comedian Alexei Sayle, in a letter to the newspaper last weekend, noting other ASA adjudications against Israel tourist adverts, wrote: "Perhaps you should now just refuse to offer any advertising space to the Israeli government, which repeatedly claims that land illegally acquired by conquest is theirs."
In an email posted by the PSC on its website, the Guardian's head of client services, Mark Finney, said that the map should not have been published.