Setting aside the current problems in Venezuela I fail to see how the mildly socialist policies of the Labour Party are likely to result in a 'Venezuela' type situation in the UK.
Firstly, Britain has a mature and stable democracy which has survived other 'socialist' initiatives such as the creation of the NHS, nationalisation of key services and industries (rail, road transport, utilities etc; not to mention the Royal Mail which was run from its inception as a national service). Whereas Venezuela has only been a nominal 'democracy' since the late 1950s, having previously been controlled by a series of military dictatorships.
The British constitution, unwritten and imperfect as it may be, has developed over 300 years. Even contemporary attempts to circumvent it have proved to be difficult as it is based on the rule of law, upheld by an independent judiciary and the separation of legislative and executive power exercised through a sovereign parliament.
It would be very hard for a would be dictator to circumvent this system, unless they had the willing acquiescence of the greater part of the population ; a population, indeed, willing to resort to, or consent to, violence should the dictator's powers be threatened (one of the inherent dangers of populism and a very sound reason for supporting the principle of parliamentary democracy).
Venezuela is not a mature democracy in any sense.
Above all, Venezuela is subject to massive corruption; it's ranked among the most corrupt countries in the world. While we might be able to cite instances of corruption in Britain and other developed countries they are on nothing like the scale of Venezuelan corruption. It is reckoned that a huge part of their wealth from oil has disappeared as a result of corruption; far from being dissipated in spending on socialist 'public expenditure' it has disappeared into the pockets of members of the regime and their associates. Can anyone, in all honesty, see corruption on such an industrial scale happening in Britain? (Though, on reflection I think that we do tolerate a degree of Right Wing corruption that positively harms our economy, bankers bonuses, money going to tax havens, tax evasion by global companies etc)
In short, I think that thinking that Britain could become like Venezuela under Corbyn is quite unrealistic. I think that continuing to be run by neo-liberal policies, coupled with the shock of Brexit, is far more likely to produce a Venezuelan result..