Federal prosecutors filed a sentencing memorandum Friday seeking a “substantial” prison term for US President Donald Trump’s former lawyer, Michael Cohen.

As set forth in the Probation Department’s Presentence Investigation Report … the applicable United States Sentencing Guidelines … range is 51 to 63 months’ imprisonment. This range reflects Cohen’s extensive, deliberate, and serious criminal conduct, and this Office submits that a substantial prison term is required to vindicate the purposes and principles of sentencing as set forth in Section 3553(a). And while the Office agrees that Cohen should receive credit for his assistance in the [Special Counsel’s Office] investigation, that credit should not approximate the credit a traditional cooperating witness would receive, given, among other reasons, Cohen’s affirmative decision not to become one. For these reasons, the Office respectfully requests that this Court impose a substantial term of imprisonment, one that reflects a modest downward variance from the applicable Guidelines range.

Also Friday, Special Counsel Robert Mueller filed his own sentencing memorandum. Mueller did not take a position on the particular sentence to be imposed but called the crimes “serious” while acknowledging Cohen’s assistance in the investigation.

Cohen, who pleaded guilty last week to lying to Congress about Trump’s dealings in Russia, is due to be sentenced next Wednesday.