Their failure created a very bad impression upon the Parliament.  All the old complaints against the Dutch were revived; and, as they had refused the offer of friendship that had been made to them, it was resolved that strong measures should be taken to obtain redress for past grievances and for the protection of English trade interests.

At the instance of St John, the famous Navigation Act was passed by the Parliament, October 9, 1651.  This Act struck a mortal blow at the Dutch carrying trade by forbidding the importation of foreign goods into English ports except in English bottoms, or in those of the countries which had produced the goods.  Scarcely less injurious was the prohibition to aliens to fish in British waters, and the withdrawal of the rights based on the Magnus Intercursus, for the maintenance of which Dutch statesmen had so long and strenuously fought.  There was consternation in Holland, and the States-General determined to send a special embassy to London.  At the same time the Estates of Holland replaced Jacob Cats by appointing the aged Adrian Pauw, a man in whose ripe judgment they had confidence, to the office of council-pensionary.  The chosen envoys were Jacob Cats and Gerard Schaep from Holland, Paulus van der Perre from Zeeland, all three representative of the two maritime and trading provinces.  They arrived in England on December 27, 1651.  Their instructions were to secure the withdrawal of the Navigation Act and to try to negotiate a new treaty of commerce on the basis of the Magnus Intercursus.  They were also to protest strongly against the action of English privateers, who, having been given letters of marque to prey upon French commerce, had been stopping and searching Dutch merchantmen on the ground that they might be carrying French goods.  The English government, however, met the Dutch complaints by raking up the long list of grievances that had stirred up a bitter feeling of popular hatred against the United Provinces in England, and by demanding reparation.  They further demanded that Dutch commanders should acknowledge England’s sovereignty by striking flag and sail and by firing a salute, whenever any of their squadrons met English ships “in the narrow seas.”

It was these last two questions, the right of search and the striking of the flag, that were to be the real causes of the outbreak of a war that was desired by neither of the two governments.  But popular feeling and the course of events was too strong for them.  The news of the seizure of their vessels, not merely by privateers, but by an English squadron under Ayscue in the West Indies, had caused intense indignation and alarm in Holland, and especially in Amsterdam.  Pressure was brought to bear on the States-General and the Admiralties, who in pursuance of economy had reduced the fleet to seventy-five ships.  It was resolved therefore, on February 22, to fit out an additional 150 vessels.  The Council of State, on hearing of this, began also to make ready for eventualities.  Negotiations were still proceeding between the two countries, when Martin Tromp, the victor of the battle of the Downs, now lieutenant-admiral of Holland, was sent to sea with fifty ships and instructions to protect Dutch merchantmen from interference, and to see that the States suffered no affront.  Nothing was actually said about the striking of the flag.