Essen, the commander of the Swedish military forces at Norway's borders, Bernadotte referred to Christian Frederick as a rebel who had probably been misled by the Danish nobility. He ordered his forces to treat all Danish officials who did not return home as outlaws, and all users of the "prince dollars" to be considered counterfeiters. Swedish troops amassed along the border to Norway, and there were daily rumours of an invasion. In spite of his open opposition to Christian Frederick, Wedel-Jarlsberg was elected as a delegate to the constitutional convention on 14 March. There were clear signs that the convention, only weeks away, would be contentious. Carsten Anker arrived in London on 24 March, where he met with an under-secretary of foreign affairs. The under-secretary rejected Anker's appeal for self-determination, and Anker found all other doors closed to him in London. On 2 April Christian Frederick sent Carsten Anker's brother Peter (1744–1832) to London as an unofficial emissary. On 3 April Carsten Anker was imprisoned for three days in debtors' prison on account of an old debt, probably at the behest of the Swedish ambassador to London. On 31 March Christian Frederick arrested officers of the naval vessels stationed in Norway as they were preparing to follow orders to bring the ships to Denmark. The ships were confiscated as ships of the Norwegian navy. On 1 April Frederick VI sent a letter to Christian Frederick, asking him to give up his efforts and return to Denmark. The possibility of disinheriting the crown prince was mentioned in the letter. Christian Frederick rejected the overture, in the same letter invoking Norway's right to self-determination and the possibility of keeping Norway under the Danish king. A few days later, Christian Frederick warned off a meeting with the Danish foreign minister Niels Rosenkrantz, pointing out that such a meeting would fuel speculation that the prince was motivated by Danish designs on Norway. Constituent Assembly Although the European powers refused to acknowledge the Norwegian independence movement, there were signs by early April that they were not inclined to support Sweden in an all-out confrontation on the matter. As time approaches for the constitutional convention, there was growing support for opposition to the treaty of Kiel, especially from Bergen. On 10 April the constitutional convention convened for the first time, at church services in Eidsvoll. The sermon caused some stir by flattering Christian Frederick in particular