Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: George Osborne today refused to match Labour's pledge not to increase VAT as a row erupted over how to balance the books after the election. The Chancellor declined to give a 'cast-iron guarantee' to match Labour's pledge not to increase VAT over the five years of the next Parliament. It came after Labour's shadow chancellor Ed Balls that Conservatives had a history of raising VAT after elections despite saying they had no plans to do so during the campaign. Scroll down for video Chancellor George Osborne declined to give a 'cast-iron guarantee' to match Labour's pledge not to increase VAT from 20 per cent over the five years of the next ParliamentLabour's Ed Balls unveils poster warning Tories will hike VAT againOsborne used first Budget in 2010 to increase rate from 17.5% to 20%Chancellor insists his plans to balance books do not require new increaseBut he repeatedly refused to match Labour's promise ahead of election 
 Question:Mr Balls claimed the _ 'have a secret plan to raise VAT again'.

Tories