73 Mr S. M. Bruce, High Commissioner in London, to Mr R. G. Menzies, Prime Minister
Cablegram 138 LONDON, 22 February 1940, 5.23 p.m.
IMMEDIATE FOR THE PRIME MINISTER MOST SECRET
Owing to reports of arms and munitions being shipped from Germany to Petsamo and Murmansk via Norwegian territorial waters and desire to stop German iron ore supplies via Narvik, the War Cabinet considering whether the situation arising out of the Altmark episode  does not present opportunity for immediate action in Norwegian territorial waters by sowing mine field thus forcing ships out.
This possibility in my view being considered in isolation and I have made strong representations down the following lines. The position has to be examined in relation to wider proposal to afford necessary support to Finland to prevent her being overwhelmed and to obtain control of Gallivare iron ore fields (Dominion Office telegrams). 
This wider proposal contemplates for its success co-operation of Norway and more particularly Sweden.
Atmosphere created with Norway as a result of action in her territorial waters would clearly render her co-operation unlikely.
Sweden while privately not adverse to action in corresponding territorial waters would be in some difficulty in responding to overtures for co-operation by Allies, following immediately upon drastic even if warranted action infringing neutrality of her fellow Scandinavian country.
Wider proposal contemplates in the very near future appeal by Finland and indication of preparedness of Allies to respond if Norway and Sweden will at least co-operate by affording facilities for volunteers and supplies to pass through their countries.
Difficulties in the way of their refusing that co-operation would disappear if within few days of appeal the Allies had taken an action which had aroused intense feeling in one if not both countries.
In my view essential to decide if major proposal to be pursued. If yes, action in Norwegian territorial waters should be postponed pending ascertainment of reactions to it. This may be forthcoming immediately as Mannerheim  being informed today of major proposals and may refuse to co-operate on grounds of insufficiency.
If necessary to abandon major proposal Norwegian action could then be taken on basis, apart from broad grounds which justify it, of stopping German arms and supplies for Russia being sent through Norwegian territorial waters.
Matter being reconsidered by War Cabinet this morning.