The price of Lotto Plus is set to increase by €1 euro from €5 euro on the 1st September.
National Lottery say the increase will allow them to offer a big prize fund. The top prize in the Lotto plus draw will increase from €500,000 to €1 million euro.
The company is denying that this is the second price increase in three years since National Lottery was taken over by a Canadian firm, Premier Lotteries Ireland.
Spokesperson, Miriam Donohoe, says the Plus game has not been increased for 16 years.
She added that a previous price hike was for the Lotto main draw. This time round the cost of a basic Lotto ticket will remain unchanged.