If you look at our governing party's donors, Big Tech is not sponsoring them. Their biggest donors are all global money-laundering operations, headed by Russian and other ex-Soviet regions and the Middle East. See Private Eye for a lot on the man who owns them (an Israeli, but one who has had fraudulent business closed by the courts in his own country).
From memory, the only other bigger donors are hedge funds benefiting from brexit volatility and British-dependent tax havens. Not big tech.