However, Pitt was greatly exercised by the Austrian defeat at Jemappes in November 1792, as this opened up all her Belgian territories to French occupation. British alarm grew when the French opened the Scheldt and offered ‘fraternity and assistance’ to all peoples seeking to break the yoke of monarchy and tyranny. On 16 November the French issued a decree asserting their right to pursue Austrian troops wherever they fled; this seemed a potential threat to the territorial integrity of Holland. On 19 November they promulgated a fresh decree offering fraternity and assistance to all nations which wished to recover their freedom. On 27 November they announced the permanent annexation of Savoy.
At the same time Pitt was pre-occupied (or professed to be) with the fear of home-grown subversion. This fear certainly frightened the more conservative Whigs. At the end of November extra troops were brought into London and defences at the Tower and the Bank of England were strengthened. On 1 December a new Royal Proclamation was issued, and a few days later Parliament was recalled. In the same month the navy mobilized and militias were called out in ten counties. Grenville informed the French ambassador Chauvelin: Britain
will never see with indifference that France shall make herself directly or indirectly sovereign of the Low Countries or the general arbitress of the rights and liberties of Europe.But on 15 December a further French decree stated that the occupied territories would be incorporated into France and that any country hostile to the principles of republican government would be regarded as an enemy. At the end of December Britain communicated a rejection of this message.
On 8 January the Aliens Act gave the Home Secretary the power to expel undesirable aliens. Fox’s view that it was unnecessary was easily voted down. The export of grain to France was halted - and here the government may have been influenced by popular demonstrations that might have reflected a combination of anti-French feeling and anxieties about food shortages. On 2 February the Bristol Journal reported:
Several towns in Cornwall were last night visited by large bodies of miners from the different works, in search of concealed corn, which they insist upon is intended for exportation to France. At Wadebridge they found about 25,000 bushels in store, which they obliged the owners to sell at reduced prices. At Looe upwards of 6,000 bushels of grain were kept by them from being shipped - but we did not hear of their committing any outrage.The Times’s opinion was:
Never was there a war more popular than the approaching one against France appears to be.Most believed that the war would be short - it was against ‘vagabonds, freebooters and Levellers’. It was against a country in turmoil - it was therefore believed that France would not be able to defend herself.
Though it was not the cause of the war, the execution of Louis XVI aroused great outrage in Britain. Pitt declared it
the foulest and most atrocious deed.Even Fox called it a deed that
stained the noblest cause that ever was in the hands of Men.On 1 Feb the Convention declared war, probably pre-empting a similar action by Britain.
But Pitt’s war policy differed from Burke’s. Burke had become a ferocious hawk, obsessive in his search for evidence of subversion and sedition at home, but Pitt did not fight the war as an ideological crusade to extirpate Jacobinism. As war loomed, he called upon France to renounce ‘all ideas of aggrandizement’ and to ‘confine herself within her own territories’. Beyond that the war aims were unclear. Did they include the capture of French colonies? If so, was this to be the type of colonial war fought by Pitt the Elder? Because the government envisaged a short war, they did not come to grips with this question - for which they were severely criticised by Fox.
On the other hand the opposition was in increasing disarray. In the closing months of 1792 Burke and his ally William Windham began urging their colleagues to support the government against the threat of French Jacobinism. In January 1793 Pitt made the Whig Lord Loughborough Lord Chancellor. In February group of Whigs under the leadership of Windham declared their separation from Fox and constituted themselves a ‘Third Party’. The Whigs were splitting. Fox urged immediate peace negotiations but Portland (the nominal leader of the party) believed that revolutionary France had to be defeated.