Sheriff James Scott ruled that “the comments were clearly directed at the State of Israel, the Israeli Army, and Israeli Army musicians”, and not targeted at “citizens of Israel” per se. “The procurator fiscal’s attempts to squeeze malice and ill will out of the agreed facts were rather strained”, he said.

The Sheriff expressed concern that to continue with the prosecution would have implications for freedom of expression generally: “if persons on a public march designed to protest against and publicise alleged crimes committed by a state and its army are afraid to name that state for fear of being charged with racially aggravated behaviour, it would render worthless their Article 10(1) rights. Presumably their placards would have to read, ‘Genocide in an unspecified state in the Middle East’; ‘Boycott an unspecified state in the Middle East’ etc.

“Having concluded that continuation of the present prosecution is not necessary or proportionate, and therefore incompetent, it seems to me that the complaint must be dismissed.”

Mr Fraser, the Procurator Fiscal Depute, said he would be appealing the ruling.

Yesterday’s ruling will disappoint the musicians whose concerts now attract regular protest. After a similar disruption of their Wigmore Hall concert last week they issued a statement claiming to “have no connection with or patronage by the [Israeli] Government”. However, organisers of their November 2009 Australia tour acknowledged that “The Israeli Government provided about $8000 towards the costs of the tour”, but explained, “this was only a minuscule proportion of the total cost.”

Outside Edinburgh Sheriff Court, supporters held banners reproducing the ‘racist’ slogans, and a number of enlarged concert programs indicating Israeli Embassy sponsorship of the quartet’s tours were on display.

SPSC chair, Mick Napier had mixed feelings about the ruling: “While this particular attempt to criminalise solidarity with Palestine has failed, British Government support for Israel continues. In England, more than 20 prison sentences - some for over 2 years - have been handed out to those who protested Israel’s massacre of 1400 mostly civilians in Gaza last year. On the subject of racism, of the 78 charged, all but two are young Muslims.

“If our case had gone to trial, it would have been Israel in the dock, not us. We had a string of witnesses from Palestine, Israel, and South Africa lined up to discuss the real racism and apartheid that Palestinians face daily. As long as the ethnic cleansing of Palestine continues, Israel’s political, cultural, and sporting ambassadors will face boycott protest similar to that faced by the racist apartheid South African regime in the last century.

“It’s time for politicians to fall into line with public opinion. Alex Salmond’s recent call for a review of trade relations with Israel is a step in the right direction, but what that means in practice remains to be seen.”