Mikrah Chevra

Plotzker Synagogue (in 1870)

Fashion Street, London E1 (in 1887),
Widegate Street, London E1 (in 1870)
(Both the above are mentioned in V. D. Lipman's "Social History of the Jews in England 1850-1950" and it is assumed that they refer to the same congregation.)

London Borough of Tower Hamlets

By 1870.

The Mikrah Synagogue, Fashion Street, is among the 21 or 22 synagogues listed by V. D. Lipman in his "Social History of the Jews in England 1850-1950" (pp120-121) as the founding members  of the Federation of Synagogues on 6 November 1887.
(A meeting had been held on 16 October 1887 to form the Federation, and the Mikrah Chevra or Plotzker Synagogue is not listed by Geoffrey Alderman in his history of "The Federation of Synagogues 1887-1987" as one of the 16 synagogues that attended the meeting, although there was a congregation named as the Fashion Court Chevra founded in 1858.)
The Jewish Year Book 1896-1897, includes a Mikvah Synagogue at  New Court. (New Court appears to be in Fashion Street) among the members of the Federation.  It is presumed that this is a separate congregation and not a typographical error.  (List of Federation congregations)

Closed after 1887 - There was a Plotsker Synagogue in Commercial Road in the1920's, but this is presumed to have been a different congregation

Orthodox - Ashkenazi

1870 - 50 members  (Social History of the Jews in England by V. D. Lipman, p.74)