A MILLION workers on the minimum wage will get a 20p per hour pay rise today, but trade unions and economists said it was not enough.

Employees aged 21 and over will receive the small rise from £6.50 to £6.70 an hour.

The increase comes six months before the minimum wage is rebranded as the mandatory national living wage, which will give workers over 25 £7.20 an hour.

Economists at the Resolution Foundation think tank welcomed the boost in salaries but warned that the “conservative” rise would result in double as many workers living on the minimum wage by 2020 — one in seven employees in the private sector.

“Today’s 20p rise is relatively conservative given the strength of the labour market,” said foundation economic analyst Adam Corlett.

“It’s also important that businesses offer low-paid staff more opportunities for promotion and progression so that they don’t get stuck on the wage floor.

“The national living wage has injected fresh energy into the debate on tackling Britain’s chronic low pay problem, but further action will be needed to secure stronger wage growth throughout the workforce.”

Trade unions were also concerned about the true value of the pay rise. Tax credit cuts from April 2016 will cost over 3 million working families an average of £34 a week.

“Giving with one hand and taking more with the other is not the way to make work pay,” said TUC general secretary Frances O’Grady.

“Slashing vital in-work benefits will serve only to push more working households into poverty.

“We won’t have a recovery for the many by taking an axe to the welfare budget.”

Her words were echoed by GMB union general secretary Paul Kenny, who argued that Chancellor George Osborne’s new £7.20 an hour rate was not a living wage.

“For the huge numbers of working families that will be hit by cuts in tax credits the answer is simple — they should join a union to fight for better pay from employers who can well afford it, as Osborne confirmed.”