| Institute of Naval Architects |
Professional/trade organisations |
|
| Institute of Petroleum Technologists |
Miscellaneous |
|
| Institute of Public Relations |
Professional/trade organisations |
|
| Institute of Race Relations |
Pressure/campaign organisations |
|
| Institute of Shipbuilders and Engineers |
Miscellaneous |
|
| Institute of Surveyors |
Professional/trade organisations |
|
| Institute of Workers' Control |
Pressure/campaign organisations |
|
| Institute of World Affairs |
Miscellaneous |
|
| International Arbitration League |
International organisations |
|
| International Co-operative Alliance |
Pressure/campaign organisations |
|
| International Federation of Cotton Spinners and Manufacturers |
Professional/trade organisations |
|
| International Federation of Trade Unions |
International organisations |
|
| International Law Association |
International organisations |
|
| International League for Peace |
International organisations |
|
| International Marxist Group |
Party-affiliated organisations |
|
| International Socialist Bureau |
International organisations |
|
| International Textile Workers' Federation |
Pressure/campaign organisations |
|
| International Working Mens' Association |
International organisations |
|
| Inter-Parliamentary Union |
Pressure/campaign organisations |
|
| Inter-Parliamentary Union for Peace and Arbitration |
International organisations |
|
| Ipswich Social Settlement |
Miscellaneous |
|
| Irish Cattle Traders and Stockowners Association |
Miscellaneous |
|
| Irish Convention |
Miscellaneous |
|
| Irish Home Rule Confederation of Great Britain |
Pressure/campaign organisations |
|
| Irish Industrial Development Association |
Pressure/campaign organisations |
|