The British government's clumsy handling of the Portuguese question and its unconvincing and ineffective attempts to justify its conduct certainly led to a decline in the reputation of Wellington's ministry, especially in Liberal circles on the Continent. Henry Knight, a frequent visitor to Paris, regretted that ‘England was no longer the object of universal approbation. She was no longer considered as the enlightened advocate of liberal principles abroad’. This negative image was due, in a great measure, to Palmela's manipulation of press treatment of the Terceira affair. Internally, however, Wellington still enjoyed the support of a substantial number of British politicians. Apart from occasional outbursts of radicalism – for example on 30 June 1830 when Brougham denounced the ministers as Wellington's ‘flatterers, his mean, fawning parasites’, the duke encountered more criticism abroad than at home. This probably explains why Lord Holland, although critical of the ministry's foreign policies, was less hostile in matters of domestic policies.

Another political mistake generally attributed to Wellington was the alleged interference of the British government in French internal affairs. According to some versions, Wellington was involved in an intrigue whereby Charles X was persuaded to replace Martignac by Polignac as President of Ministers. Charles's speech at the opening of the French Chambers on 2 March 1830 seemed like a declaration of war on the opposition, when he warned that any attempt to obstruct his government would be defeated by his strong commitment to the maintenance of public order. Charles's threats materialized a few days later, when, on 19 March, the Chamber of Deputies was summarily prorogued to 1 September. This measure was followed by its dissolution on 16 May and the electoral colleges summoned for 23 June and 5 July to elect a new Parliament. But the French Liberals were determined to thwart the king and Polignac. As Morgan observed, ‘The guard of resistance was simultaneously mounted; and the press, the free press, took the initiative, and formed the videttes of the great force of public opinion.’ As a consequence while the opposition obtained a comfortable majority of more than a hundred votes, the government faced an acute dilemma.

Rather than accept the nation's verdict, Charles, imagining that his life was endangered by some impending coup, decided on extreme measures and effectively tore up the Charter granted by Louis XVIII in 1814.