Karhoo is the new challenger to Uber, offering a “marketplace” for existing minicab firms to compete for your lift. Announcing its expansion today in Parliament, a gathering of taxi firm operators, politicians, and even a GMB representative turned up to hear the British CEO Daniel Ishag talk-up the firm’s three to five minute wait time in central London. The GMB private hire drivers’ union is this week challenging Uber over workers’ pay in the Central London Tribunal. Acting as an aggregator for minicabs, Karhoo is seeking to get around all the difficult TfL regulations, letting cab firms sort it out for themselves. Karhoo handing out £25 gift cards for MPs in attendance doesn’t do them any harm, either…