JAR-OPS 1.465 VFR Operating minima
(See Appendix 1 to JAR–OPS
1.465)
(a) An operator shall ensure that:
(1) VFR flights are conducted in
accordance with the Visual Flight Rules and in
accordance with the Table in Appendix 1 to
JAR–OPS 1.465.
(2) Special VFR flights are not
commenced when the visibility is less than 3 km
and not otherwise conducted when the visibility
is less than 1·5 km.
.. So you will not get a clearance to take off.
However,
ICAO requires only 1500 meters to commence SVFR or enter a CTR as SVFR.
Can't find a online reference, sorry.
American FAR's require 1 Stat Mile, which complies more or less with ICAO:
Electronic Code of Federal Regulations: