Miguel was becoming isolated and, worse still, he was losing control over his ruffians – if indeed he ever had any. The situation had become worse after the death of Carlota Joaquina on 7 January 1830. Despite her many faults, the Dowager Queen had had an enormous influence over her wayward son, not all of it bad. Her death was followed, two months later, by that of the Marques de Chaves, one of Miguel's most effective supporters. Worst of all, on 1 July 1831, during the French blockade of the Tagus as a response to the mistreatments imposed by the Portuguese authorities to several French citizens, Miguel had been forced to sign a Carta Régia accepting the resignation of his chief minister, the Duque de Cadaval – on the questionable grounds of ill health. The next day, the old ultra- royalist and sanguinary Conde de Basto was appointed acting chief minister. Under the administration of Basto, whose cruelty was equalled only by his incompetence, Portugal descended into an orgy of violence.

Palmerston's tardiness in committing himself unequivocally to the Portuguese Liberals stemmed from his doubts about Pedro, especially his unstable character and incapacity to give serious or sustained commitment to any business – a characteristic inherited from his father. Talleyrand expressed similar reservations about Pedro in a conversation with Resende in August 1831, arguing that it was essential that Pedro clarify his plans. Yet, given to the increasing violence of Miguel's regime, Palmerston was coming to the conclusion that the Liberals were the only acceptable solution for Portugal, especially after Pedro's declaration that the English predominance would be fully respected after her daughter's restoration to the throne. In mid- September, Palmerston told Asseca that his government was not trustworthy and that Miguel could not count on British aid. Perhaps as a result of this conversation, Asseca decided that it was useless to remain in London and on 20 September, after selling all his furniture, left for Falmouth to embark for Lisbon. He had submitted his resignation on 10 August, insisting in a letter to Santarem that there was no point in hoping that the present British government would work towards the reestablishment of the diplomatic relations between the two countries.