LONDON (Reuters) – A planned increase in British social security contributions from workers and employers will go ahead in April, Prime Minister Boris Johnson and finance minister Rishi Sunak said, despite calls to scrap the rise due to the strain on household budgets. With surging inflation exacerbating a cost-of-living squeeze, the government has faced growing pressure, including from some of its own Conservative lawmakers, to delay or cancel a new health and social care levy that will see the rate of National Insurance rise by 1.25 percentage points. Some British newspapers have speculated …