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                                                                EXHIBIT 23.1


               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS


We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3 No. 333-32760) and related Prospectus of Global
TeleSystems Group, Inc. for the registration of 4,709,695 shares of its common
stock and to the incorporation by reference therein of our report dated February
4, 2000, with respect to the consolidated financial statements and schedule of
Global TeleSystems Group, Inc. included in its Annual Report (Form 10-K) for the
year ended December 31, 1999, filed with the Securities and Exchange Commission.

                                                /s/ Ernst & Young LLP


McLean, Virginia
April 19, 2000