May 7 2015: "We will not raise VAT, National Insurance contributions or income tax". Conservative Government in election campaign.
March 8 2017: 'The main rate of Class 4 National Insurance contributions for the self-employed to increase from 9% to 10% in April 2018 and 11% in April 2019'. Conservative Party Budget
The surprising thing is not the broken a manifesto pledge, we all remember the 'NHS is safe in our hands' pledge while the Tories were cutting funding and running it down, but the fact that anyone could be surprised by it.
The 'Nasty Party' tag is richly deserved.