The cost of filling up a family car has risen by £5 since the start of the year as petrol prices at UK forecourts hit a five-month high. Ongoing conflict in the Middle East is being blamed for the sharpest weekly rise since August last year, which has seen 1.6p be added to the price of a litre in the last week. The average charge for a litre of petrol, according to government data, currently stands at 148.5p and motoring experts expect it will continue to rise. Diesel is also at its most expensive since November and now stands at an average of 157.5p says the latest data. Motoring organisation…