Under the Equality Act 2010, an education provider is obliged not to discriminate against students in their service provisions (including resources and delivery of teaching) and you should have a plan in place for ensuring inclusion. Making sure that disabled students have access to the relevant learning information on your website should be a part of that plan.
E-learning authors and institutions must take steps (as are reasonable in the circumstances) to ensure that e-learning environments and materials are accessible to students with disabilities. They should ensure that substantial disadvantage does not occur. Further information can be found in the Accessibility section of the JISC Legal website.
Of course, what is considered reasonable will always depend on the circumstances of a particular case. In terms of e-learning development and authoring, there is no case law to aid in setting boundaries. However, you can find examples and advice about providing an accessible learning experience from the JISC Techdis service (please note that you may need to take into account factors such as effective learning experience, ease of access to information, and current good practice in the sector).
Sometimes there are valid reasons why e-learning content can't be provided in an accessible form (for instance, copyright or licensing restrictions, or excessive cost). In these situations, e-learning authors should work with their institutions to consider alternative ways to make that material accessible. This might include providing students with assistance in accessing the e-learning environment, or providing materials offline, or a combination of various approaches.
For a readable explanation of the up-to-date law in this area, a good starting place is the Guidance for Education Providers:Further and Higher Education available from the Commission for Equality and Human Rights website.
The practical guidance at the University of Strathclyde Teachability Project is still useful in this area.
Bear in mind that, in addition to legal duties concerning accessibility, your institution will also have to deal with other legal issues, such as Copyright and Data Protection. JISC Legal also provides advice and guidance on these issues.