The party says the same Tory MPs have applied to use Commons time to ask both ministers easy questions, claiming the ruse reduces the amount of time the ministers can face under real scrutiny.
Labour said the same 10 MPs, including Tories Andrea Leadsom and David Amess, entered the draw for both last week's Scottish Questions and this week's Welsh Questions. The party says the others included Harriet Baldwin, who is keen to reform the Barnett formula, the calculation which decides how much money Scotland gets as a share of public spending.
The ministers come from different parties with Scottish Secretary Michael Moore a LibDem and Welsh Secretary David Jones a Conservative.
Labour's shadow Welsh secretary Owen Smith said: "Tory whips are so embarrassed at their party's narrow reach that they have to put up these rent-a-question MPs, who represent areas hundreds of miles away from Scotland and Wales and who are prepared to ask whatever they're told, as human shields for the Government."
A Downing Street source said the claims were "rubbish".