Quoting Jerzy Łazor’s ‘Control and Regulation of Capital Flows between Poland and Palestine in the Interwar Period’ in Foreign Financial Institutions & National Financial Systems, pages 233–235:

In the 1930s impoverished Polish Jews found it hard to procure the necessary funds, while richer strata of the Jewish community were less interested in migration. Now the situation worsened. Both Polish and Zionist officials understood that a new solution was needed, and studied the [Fascist] system known as Haʻavarah as a successful model for such an arrangement.

Within Haʻavarah, which had been created in 1933, emigrating German Jews would transfer their assets to a central agency, which used them to finance exports of [Fascist] products to Palestine. Emigrants would then receive money from the sale of these products, losing on average about 35 per cent of their initial capital payments. This allowed [Fascist] goods in Palestine to be sold below market prices, and their exports surged.

The system provoked a serious debate both in the Jewish diaspora, and in the jishuv (the Jewish society in Palestine). It was created at roughly the same time as the boycott movement, initiated by European Jews, and aimed at limiting imports from [the Third Reich]. Jews in Europe felt betrayed. Despite its moral and political ambiguities, Haʻavarah proved to be an economic success. It allowed some 20,000 people to come to Palestine, bringing with them around six million £P.²⁸

As early as May 1936, a Palestinian delegation came to Poland to negotiate a transfer agreement. It included two former Polish MPs: Fiszel Rottenstreich and Icchak Grünbaum. The third member of the delegation — Dr. Salheimer — was particularly interesting, since his home institution, the Anglo-Palestine Bank, was responsible for the Palestinian part of Haʻavarah operations.

The situation soon became more complicated. Joszua Farbstein, another former Polish MP and erstwhile head of the Department of Industry and Commerce of the Jewish Agency Executive, came to Poland at the same time. The press was rife with speculation and accused Farbstein of attempting to negotiate with the Polish government on his own account. I found no traces of this in Polish archives.

Farbstein was not the only Palestinian guest in Poland at the time: Moussa Chelouche, head of the Palestinian–Polish Chamber of Commerce in Tel Aviv, was another. Chelouche, an important figure in the Ashrai Bank and the Immigrant’s Bank Poland–Palestine Ltd, allegedly tried to dissuade the Polish government from accepting the Anglo-Palestine Bank as a major component of the new transfer. Again, I was not able to find any confirmation of these actions, beyond allegations in the Palestinian press.

Finally, Poland was in negotiations over their ‘marriage of convenience’ with the revisionist movement. Both sides had to tread lightly.²⁹

After Rottenstreich’s anti-Polish speech in August 1936 the Poles refused to talk to him. Further negotiations were thus concluded with Grünbaum alone.³⁰ Grünbaum was no novice. An important figure in Jewish interwar politics in Poland, he had been one of the creators of the minority bloc in the Sejm.

At the same time, institutions in Palestine — including the Anglo-Palestine Bank and the Executive of the Jewish Agency — tried to influence Polish officials through their representatives in Palestine. Since Bank P.K.O. was a plausible Polish choice for the main bank of the new transfer system, particular pressure was put on this subject. The director of its Tel Aviv branch, Tadeusz Piech, was told that his bank was too small, and reminded that it had only survived the banking runs in 1935–1936 with the help of the Anglo-Palestine Bank.³¹

Palestinian Jews insisted that the new arrangement should not threaten Haʻavarah. Since the list of Polish and [Fascist] goods competing on the Palestinian market was fairly long, a successful agreement with Poland could hurt Haʻavarah. Many considered it crucial for the development of the jishuv: it guaranteed a substantial flow of capital combined with a relatively low level of capitalist immigration: an outcome which went hand in hand with ruling Zionist ideology.

Polish consuls noted that the Jews’ insistence on the rôle of the Anglo-Palestine Bank was a sure sign that the Haʻavarah was considered more important than a possible agreement with Poland (although this logic seems a bit flawed). It was probably understood in Palestine that Poland would not be able to provide the amount of capital [that] the Jews needed (and which they were getting from [the Third Reich]). Moreover, with the Haʻavarah playing such an important rôle, there was no place for a particularly strong rise in Polish exports.³²

(See pages 235–245 if you have time to read more.)