Ponsonby was, therefore, obliged to join with his colleagues in advising the Porte to modify the _firman_ of February 13. Their representations, combined with an intimation from Baron Stürmer that Austria[705] would withdraw from the alliance if her counsels were disregarded, soon produced the desired effect. On April 14, Ponsonby was able to report that the Divan had decided that the succession of Mehemet Ali should be regulated in accordance with the principle of primogeniture, that he should have the power of dealing with the promotion of all officers below the rank of brigadier-general, and that the amount of his tribute should be reduced.[706] Nevertheless, some weeks elapsed before the Porte could be induced to embody these concessions in a new _firman_. For this delay Ponsonby was in no way responsible. On the contrary, he appears to have entered a vigorous protest against the procrastinating policy of the Turkish ministers.[707] Greatly to Metternich's annoyance, however, Palmerston persisted in refusing to declare that the objects of the Treaty of July had been fully achieved. The French government, therefore, continued to withhold from Baron Bourqueney the authority to sign the Convention of the Straits. But M. Guizot was consumed with anxiety to conclude the affair, and in consequence of Palmerston's attitude he was now compelled to instruct his agents in Egypt to urge Mehemet Ali to accept the amended _firman_, which they were to declare was no longer open to any reasonable objections.[708] Mehemet Ali was too astute to offer any further resistance. On July 8, 1841, Ponsonby's singularly laconic despatch reached London, announcing "the satisfactory intelligence"[709] that the Pasha had accepted the new _firman_, and had made a complete submission to the Sultan. The representatives of the Powers which were parties to the Treaty of July, thereupon, affixed their signatures to the protocol, which they had initialed four months before, announcing that the objects of their alliance had been fully attained. Three days later the isolation of France was formally terminated. On July 13, the plenipotentiaries of Great Britain, Austria, Russia, Prussia and France signed the Convention of the Straits by which their respective Sovereigns pledged themselves to uphold the principle of the closure of the Dardanelles and the Bosphorus to the warships of the Powers. The conclusion of the Convention of the Straits was the last important act of the Melbourne government. After sustaining a defeat on the sugar question, on May 18, ministers, in the subsequent motion of want of confidence brought forward by Sir Robert Peel, found themselves in a minority of one. At the general elections which followed, the Conservatives obtained a decisive victory. The Whigs, in consequence, retired from office, and Lord Palmerston was replaced at the Foreign Office by Lord Aberdeen.