ZANU PF has seized total control of all grain coming into the country by barring private traders from importing staple cereals.
The move will worsen the situation for Zimbabweans who have been teetering on the verge of starvation since 2000, when ZANU PF embarked on its chaotic land reform programme.
Two years ago the unity government issued licences to private importers when it became clear that the state-owned Grain Marketing Board (GMB) was failing to feed the starving nation, with stocks at its silos falling below critical levels.
But that arrangement was last month reversed by ZANU PF Agriculture Minister Joseph Made, despite millions of Zimbabweans still facing starvation.
The milling industry says it requires at least 3,500 metric tonnes of maize daily to meet national demand, which the state-owned GMB has been failing to supply, raising fears of hunger and starvation.
"The Grain Millers Association of Zimbabwe is deeply saddened to note the Ministry of Agriculture has banned imports of grain but continues to issue massive import permits of maize meal to companies owned by senior politicians," the group said in a letter to government, and quoted in a Daily News Tuesday report.
The millers say the decision to exclude them from the maize import sector was taken without prior notice and as a result they are concerned that traders who had already paid, but not taken delivery of maize, will lose.
The new GMB maize prices to millers will increase the retail price of a 10kg bag of maize-meal from $6.41 to $7.13, the millers group added.
Some observers have raised concern that restricting imports to the traditionally inept GMB will lead to shortages and create a black market for the staple grain.
"We knew that it was a matter of time before ZANU PF reverted to its default position," MDC legislator and ex-minister Priscillah Misihairabwi-Mushonga said on Tuesday.
She said Zimbabweans should brace themselves for tough times ahead as the GMB will not manage to provide the country with adequate food.
"It is total madness to give the GMB a bigger responsibility when it was failing even with other players assisting. During the life of the inclusive government we had a lot of discussions about the incompetency at the GMB which was even failing to distribute grain that was in its silos.
"The government says it has no money for anything, so how will they ensure that the GMB imports sufficient grain for Zimbabweans," the ex-Minister of Integration in the unity government said.
In a related development, the government has reportedly entered into a secret deal with South African company ASP to supply 150,000 metric tonnes of maize meal.
But so far, the SA firm has only managed to deliver 950 metric tonnes, according to the Daily News.
Under the shady deal both the Zim government and ASP will "keep confidential all information, whether oral or written concerning the business and affairs of the other," the newspaper reported.
Humanitarian aid agency the World Food Programme says food insecurity in the country is at its highest since 2009, and estimates 2.2 million Zimbabweans need assistance.
The agency revealed in December that it was reducing rations to beneficiaries by half, in order to stretch out the food.
"We've had to cut rations for one million of our beneficiaries in recent months and there are likely to be deeper cuts as from next month (February)," the aid agency said in a statement.