The first role of the English in the Darien Scheme, according to Dennis Hidalgo, was to be in the realm of capital; although King William allowed the formation of the Company of Scotland, the East India Company promptly lobbied the House of Lords to bar English capital from being invested in the company, as they scented a potential competitor. This did not necessarily damage the scheme as a whole however, as the indifferent response of the English provoked a groundswell of support for the expedition in Scotland, with £400,000 being invested in the company by the populace, a vast amount estimated to be nearly half the capital available to the Scots (Prebble, 1968).

The English were then to interfere again (or rather, not interfere), after the colonists actually arrived in Darien. Inexperienced with colonisation, the colony quickly succumbed to a lack of food and tropical disease, but little help was forthcoming from the English colonies in the Caribbean, who had been prohibited from trading with the burgeoning colony.

Therefore, it would be plausible to see England's policy towards Darien as something of sabotage by sitting-on-hands, mostly directed by competing commercial interests within England, rather than one or the other. There was little in the way of active destruction of Scottish aspirations, but with no English assistance forthcoming, the colony, once ailing, had no means of recovery.

Sources:

Dennis Hidalgo, 'To Get Rich for Our Homeland: The Company of Scotland and the Colonization of the Darién', Colonial Latin American Historical Review 10 (2001), 311-350

John Prebble, The Darien Disaster (New York: Holt, Rinehart and Winston, 1968)

Further reading/Archival Recommendations:

Darien Papers, Special Collection, University of Glasgow Library (contains a raft of primary and secondary material on the subject)

Michael Lynch, Scotland: A New History (London: Pimlico, 1992)

Philip Lawson, The East India Company: A History (London: Longman, 1993)

Bruce Lenman, An Economic History of Modern Scotland, 1660-1976 (London: Batsford, 1977)

I would like to end this by making no claims to an especial knowledge of the Darien scheme nor an active research interest in this particular period or topic, however, I have attempted to provide an answer in the most scholarly way that I can.