Exhibit 23.3

CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" and to the use of our report dated March 29, 2002, with respect to the financial statements of Aegis Research Corporation for the year ended December 31, 2001 included in Amendement No. 1 to the Registration Statement (Form S-1 No. 333-101226) of ManTech International Corporation for the registration of 6,150,000 shares of its Class A common stock.

/s/ Ernst & Young LLP

McLean, Virginia

November 27, 2002

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