Using the two sources below, evaluate the claim that minor parties have had a decisive influence on UK policy in the 2010s. Source A: an extract from a newspaper analysis, 2014: "UKIP's surge in European and local vote shares has forced the Conservative leadership to promise a referendum on EU membership, reshaping Conservative policy on Europe." Source B: a 2019 academic commentary: "Greens and environmental NGOs raised climate salience throughout the 2010s leading to mainstream parties adopting net zero targets and more detailed climate policy by 2019, but the final policy content was often substantially adapted by major-party strategists."
(Total for Question 12 is 12 marks)