spend of UK-facing operators on TV adverts since 2012 is nigh on £500m, according to figures in a report compiled for the Guardian by media analysts Nielsen.

According to the posted figures, there was a 46% increase in spending on TV spots between 2012 and 2015, rising from £81.2m to £118.5m.

A total of £465m has been shelled out on TV adverts since 2012, which rises to £631m when taking into account the reported spend by lottery operators.

Figures for 2016 up to the end of May reveal that UK operators have thus far spent £51.4m on TV advertising, putting the projected total at a record £123.4m.

Growth in TV advertising spend by UK operators has risen since the 2007 passage of the Gambling Act, which allowed advertising for sports betting, online casinos and poker alongside the already permitted lottery, bingo and football pools.

However, gambling adverts will not be seen before the 9pm watershed under the terms of a voluntary code adopted by operators, with the exemption of adverts related to major sporting events.

UK communications regulator Ofcom said in 2013 that the number of gambling adverts on TV had risen from 234,000 in 2007 to 1.39m in 2013.

While TV advertising spend by operators may have gone up in the last few years, complaints levelled against them have decreased.

Figures from the Advertising Standards Authority show that 1,152 complaints were lodged in 2012, but have fallen every year, with a figure of 956 recorded for 2015.