WINTHROP
REALTY TRUST                      
FORM 10-Q - MARCH 31, 2007

Exhibit 31.1

CERTIFICATION

I, Michael L.
Ashner, certify that:

| | 1. | I
have reviewed this Quarterly Report on Form 10-Q of  Winthrop Realty Trust;
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| | 2. | Based
on my knowledge,  this report does not contain any untrue statement of a material fact or
omit to state a material                fact necessary to make the statements  made, in
light of the  circumstances  under which such  statements were made, not
               misleading with respect to the period covered by this report;
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| | 3. | Based
on my  knowledge,  the financial  statements,  and other  financial  information
 included in this report,  fairly                present in all material respects the
financial condition,  results of operations and cash flows of the Registrant as of,
               and for, the periods presented in this report;
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| | 4. | The
Registrants  other certifying  officer and I are responsible for establishing and
maintaining  disclosure  controls                and procedures (as defined in Exchange
Act Rules 13a-15(e) and 15d-15(e)) for the Registrant and have:
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| | (a) | Designed
such  disclosure  controls and  procedures,  or caused such  disclosure  controls and
procedures to be                         designed under our supervision,  to ensure that
material information relating to the registrant,  including its
                        consolidated subsidiaries, is made known to us by others within
those entities,  particularly during the period                         in which this
report is being prepared;
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| | (b) | Designed
 such internal  control over  financial  reporting,  or caused such  internal  control
over  financial                         reporting to be designed under our supervision,
 to provide reasonable  assurance  regarding the reliability of
                        financial  reporting and the  preparation  of financial
 statements  for external  purposes in accordance  with                         generally
accepted accounting principles;
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| | (c) | Evaluated
the  effectiveness  of the  Registrants  disclosure  controls and  procedures  and
presented in this                         report our conclusions about the effectiveness
of the disclosure controls and procedures,  as of the end of the
                        period covered by this report based on such evaluation; and
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| | (d) | Disclosed
 in this report any changes in the  Registrants  internal  control  over  financial
 reporting  that                         occurred during the Registrants  most recent
fiscal quarter,  that has materially  affected,  or is reasonably
                        likely to materially affect, the Registrants internal control
over financial reporting; and
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| | 5. | The
Registrants other certifying officer and I have disclosed,  based on our most recent
evaluation of internal control                over financial  reporting,  to the
Registrants  auditors and the audit committee of the Registrants board of directors
               (or persons performing the equivalent functions):
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| |  | 
| |  | 

| | (a) | All
 significant  deficiencies  and material  weaknesses  in the design or  operation of
internal  control over                         financial  reporting  which are
 reasonably  likely to  adversely  affect the  Registrants  ability to record,
                        process, summarize and report financial information; and
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| | (b) | Any
fraud, whether or not material,  that involves management or other employees who have a
significant role in                         the Registrants internal control over
financial reporting.
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|                    |  |                        
|------------------- |  | -----------------------
|                    |  |                        
|Date:  May 11, 2007 |  | /s/ Michael L. Ashner  
|                    |  |                        
|                    |  | Michael L. Ashner      
|                    |  | Chief Executive Officer