The second annual LabourStart Global Solidarity Conference held in Istanbul last weekend was supposed to be a celebration of all that unites us in the international labour movement. Participants came from nearly 30 countries from a wide range of unions. Some were delegates representing their union on an official basis (such as a couple from the RMT here in Britain). Four came to represent the global union federations. Others were self-selected, activists in various labour and human rights organisations.

And the conference began with a concrete act of solidarity as well, on a Turkish picket line. Two bus-loads of international delegates came to support locked out workers at GEA, a German-owned metal company. To those who were there, it was an unforgettable event.

But others came to the conference with a different agenda in mind.

A handful of Turkish far-left activists, led by an English ex-pat (reportedly an SWP member) came to protest the participation of “representatives of the racist Zionist Histadrut” at the conference. By this they meant two of the Israelis who attended, and also myself (the founding editor of LabourStart).

They began by circulating a resolution supporting boycotts, divestments and sanctions (BDS) against the Jewish state. They persisted with this, even though they were told that the Global Solidarity Conference is not a decision-making body. Oh, and a minor point: there were no Histadrut representatives at the conference. They had been invited but did not show up.

But then the BDS campaigners decided to ramp things up. A workshop was scheduled on the subject of “Echoes of the Arab Spring”. The speakers included an American trade unionist on the subject of Occupy Wall Street, an Iraqi Kurdish activist on the 62-day long uprising earlier this year, and a young Israeli from the Working Students and Youth on the massive social protest movement in his country that drew hundreds of thousands into the streets.

The anti-Israel campaigners attempted to break up that session, but were persuaded to leave the room. (Which they did by slamming the door loudly.) All the Arab and Kurdish delegates stayed. And a very interesting discussion was held — including a vigorous dispute between two Iraqi Kurdish union leaders.

We emerged from that workshop to find the conference venue covered with hand-drawn posters saying that the Israelis were not welcome there.

All of this played against a background of rumors and mistrust, particularly among some of the North African delegates.

Behind the scenes, however, private meetings were held and in an atmosphere of complete transparency and openness, we discussed it all. Everyone put their cards on the table. And after that first morning, the anti-Israel campaigners were isolated, receiving no support from the Arab delegates. In fact, at the closing session, following a rant against Israel by a Turkish leftist, a North African trade unionist rose to speak against the efforts to disrupt and divide.

All of this turned out to be a bit of a side show, as the real work of the conference brought together very diverse groups to discuss the critical issues facing trade unionists everywhere.

Conference plenaries were addressed by general secretaries of two Turkish unions, a Tunisian union leader, and – by video – Sharan Burrow, the general secretary of the International Trade Union Confederation.

There were workshops on precarious work, the role of women in the trade union movement, social media, labour video, global campaigning, migrant labour and much more.

There were country and regional specific workshops on the struggles in Bahrain, the Arab Spring, sub-Saharan Africa and East Asia.

There were two excellent workshops on Palestine featuring both official representatives of the mainstream Palestinian unions as well as smaller, alternative groups. One focussed on the historic strike by Palestinian quarry workers which had been the subject of a recent LabourStart campaign.

The Arab delegates stayed on for another day to meet with LabourStart and the AFL-CIO’s Solidarity Center to discuss future campaigns and joint work in a very productive and open discussion.

Everyone except the anti-Israel campaigners seemed to understand that something amazing was happening at the conference. As veteran Canadian trade unionist Derek Blackadder put it, the conference could be summed up as “100 unions, 30 countries, one class.” The singing of the Internationale, led by a hastily-assembled multinational choir, was especially stirring.

In the end, the attempt to disrupt the conference failed. But it highlighted what the pro-BDS campaigners were all about. They were not remotely interested in building global labour solidarity. All they wanted to do was to show their hatred of Israelis, all Israelis, even those who were on the left, who supported the rights of Palestinians.

In behaving as they did, they showed everyone — including many who might have been sympathetic to their cause — their true colours.